Fact Check: C# .NET Full-Stack Developer Interview Answers Accuracy
Generally Credible
48 verified, 5 misleading, 2 false, 0 unverifiable out of 55 claims analyzed
The transcript is a mock interview for a full-stack developer position. The candidate demonstrates a solid, practical understanding of core C#, .NET, SQL, and React concepts. Most factual claims are accurate and reflect standard industry knowledge. However, the analysis reveals several minor inaccuracies. For example, the candidate mistakenly states the async keyword makes a method synchronous, when it makes it asynchronous. There is also the erroneous mention of a non-existent "Generation 3" in .NET garbage collection. Explanations of execution models for IEnumerable vs. IQueryable were slightly oversimplified, and some statements about SQL command rollback behavior were not entirely precise. Despite these points, the candidate correctly explains many complex topics like dependency injection lifecycles, the virtual DOM, and ACID properties. The interview paints a picture of a competent developer who would benefit from deepening knowledge of certain nuanced technical details.
Claims analysis
IEnumerable uses deferred execution.
This is correct. IEnumerable indeed supports deferred execution; the query is not executed until the collection is iterated.
IQueryable uses immediate execution.
This is misleading. The core distinction is that IQueryable is designed for querying external data sources like databases and allows the query to be built and then executed remotely. The execution (e.g., .ToList()) triggers immediate execution against the data source, but the query building itself is deferred. The statement is oversimplified.
IQueryable is better for performance than IEnumerable.
Generally correct. IQueryable can be more performant for database queries as it translates to SQL and filters at the database level, reducing data transfer. IEnumerable requires loading all data into memory before filtering.
Boxing converts a value type to a reference type.
This is a correct definition of boxing.
Unboxing converts a reference type to a value type.
This is a correct definition of unboxing, though it specifically converts an object type back to a value type.
ArrayList is the best real-time example for boxing and unboxing.
This is acceptable. ArrayList stores objects, so adding a value type (e.g., int) causes boxing, and retrieving it causes unboxing.
The `async` keyword defines a method as synchronous.
This is incorrect. The `async` keyword defines a method as asynchronous, not synchronous. The rest of the explanation about how `await` works is otherwise accurate.
A thread is the smallest execution unit of work handled by the operating system.
This is correct. A thread is indeed the smallest unit of execution managed by the OS.
Thread pool is pre-created pool of threads operated by .NET CLR.
Correct. The CLR manages a thread pool, reducing the overhead of creating threads manually.
Task is the abstraction for a thread pool.
This is a reasonable simplification. A Task represents an asynchronous operation and is scheduled on the thread pool by default.
Dependency injection is a design pattern where classes receive dependencies from outside.
This is an accurate description of Dependency Injection (DI).
Abstract class contains both concrete and abstract methods.
This is correct. An abstract class can have both fully implemented (concrete) methods and abstract methods.
Interface is a contract with only method declarations.
This is correct. Traditionally, interfaces only declare method signatures. (Note: C# 8.0+ allows default interface methods, but the core concept remains.).
Generation 0 objects are short-lived and cleaned up frequently.
Correct. Generation 0 contains newly created, short-lived objects.
Generation 2 cleans up objects that survived Gen 1.
This is correct. Objects that survive Gen 0 collections are promoted to Gen 1, and those that survive Gen 1 are promoted to Gen 2.
Generation 3 is for global variables and constants.
This is incorrect. .NET garbage collection has only three generations (0, 1, 2). Gen 2 is for long-lived objects. There is no Gen 3.
Deferred execution means the query executes only when iterated.
This is an accurate description of deferred/ lazy execution.
Immediate execution is supported by IQueryable.
Misleading. IQueryable itself supports deferred execution of query building. The methods like .ToList() or .ToArray() trigger immediate execution, but they are not unique to IQueryable.
First() throws an exception if no matching element is found.
This is correct. First() will throw an InvalidOperationException.
FirstOrDefault() returns null if no match is found.
This is correct for reference types. It returns the default value (null for reference types).
Single() throws an exception if no match or more than one match is found.
This is correct. Single() requires exactly one element.
.NET Framework supports only Windows.
This is correct. The classic .NET Framework is Windows-only.
.NET Core supports cross-platform (Windows, Linux, macOS).
This is correct. .NET Core is designed for cross-platform development.
AddTransient creates a new instance for every request for the service.
Correct. AddTransient provides a new instance of the service every time it is requested.
AddScoped creates an instance per HTTP request.
Correct. AddScoped provides one instance per scope (typically per HTTP request).
AddSingleton creates a single instance for the entire application.
Correct. AddSingleton provides one instance for the application's lifetime.
JWT token contains claims like username, password, and role.
Misleading but understandable. A JWT token contains claims, which are statements about the user. It is bad practice to include a password in a JWT. More accurately, it contains a user identifier and roles.
Authentication is 'who you are', authorization is 'what you can do'.
This is a standard and accurate differentiation.
Repository pattern acts as a bridge between data access layer and DB.
This is a good description of the Repository pattern.
Entity Framework Core is an Object-Relational Mapper (ORM).
This is correct.
API versioning prevents breaking changes for existing clients.
This is the core purpose of API versioning.
Caching stores data to avoid repetitive database calls.
This is the basic concept of caching.
Clustered index is related to primary key.
Correct. By default, the primary key creates a clustered index.
Clustered index physically stores and sorts the data.
Correct.
Normalization types are 1NF, 2NF, 3NF, and BCNF.
The common normal forms are indeed 1NF, 2NF, 3NF, and BCNF.
DELETE can be rolled back in a transaction.
Correct. DELETE operations are logged and can be rolled back.
TRUNCATE removes all records and cannot be rolled back.
Misleading. TRUNCATE removes all rows and logs only page deallocations, making it minimally logged. In SQL Server, it can be rolled back in a transaction, contrary to the candidate's statement.
DROP removes the table structure and cannot be rolled back.
Misleading. Like TRUNCATE, DDL statements like DROP can be rolled back if executed within a transaction.
TRUNCATE is faster than DELETE.
Correct. TRUNCATE is faster as it uses fewer system and transaction log resources.
INNER JOIN returns records matched in both tables.
Correct.
Stored procedures can perform CRUD operations.
Correct.
Functions cannot perform CRUD operations.
Correct for SQL Server. Functions are read-only and cannot modify data.
ACID stands for Atomicity, Consistency, Isolation, Durability.
This is the correct definition of ACID properties.
Consistency means the system should be in a valid state.
This (provided by the interviewer) is accurate.
React uses a Virtual DOM for faster UI updates.
This is a core concept of React.
Diffing algorithm is used to find changes between virtual DOMs.
Correct.
useState is for managing state in functional components.
Correct.
useEffect handles side effects and lifecycle methods.
Correct.
Controlled components use useState to form data.
Correct.
Uncontrolled components form data is handled by DOM using useRef.
Correct.
Props are immutable and passed from parent to child.
Correct.
State is mutable and can cause re-renders.
Correct.
Redux has core concepts: store, dispatch, and reducer.
This is accurate, though actions are also a key concept.
Keys in React lists help identify items uniquely.
Correct.
Code splitting enables lazy loading of code.
Correct.
Hi Arun. >> Hi Alan. Good good evening.
>> How's your day? >> Yeah, it's pretty good. >> Okay.
So, can we start with your intro? >> Yeah, sure. My name is Arun. I'm a net fullstack developer having 3.5 years of
experience in XYZ company. I specialized with C.NET core web API, ReactJS and SQL server.
>> Okay. >> This is the short intro about me. >> Uh without late, let's jump into your
interview. >> Yeah, sure. Alcala. >> Let's start with a C# questions.
>> Okay. So like can you explain me the difference between I innumerable and I
queriable? >> Yeah, I innumerable and I queryable are both for querying the data. But the key
difference between when and where the execution happens. uh I innumerable
it deals with the data collections and the execution uh supports is a deferred execution
whereas I queryable works with database uh entities and this uh supports immediate
execution. >> Okay. >> Yeah. So like when would you use each?
>> Okay. Um if suppose we have a database query when we use uh filtering and two list
then it will uh execute immediately. This is the example for I queryable. Whereas
>> Mhm. >> we have the SQL query and after loading the data means after using uh dot2 list
then that memory will load into the inmemory then filtering happens after that data loading. So this is the
example for innumerable in our project. uh generally we have the code like we will do the first filtering then we will
do the immediate execution means two uh list at last so that it won't load the data it at first
and finally it will give the data after um happening the querying at database side so I queryable is better for
performance than I innumerable Right. Next question. Explain boxing and unboxing with separate time.
>> Yeah. Okay. Uh boxing and unboxing are the uh mechanisms that converts value type to reference type and vice
versa. And sorry u boxing means converting value type object to reference type whereas unboxing means
object type to value type. In a real time for example array list is the best example for this boxing and
unboxing. When an element is adding into the array list it is known as boxing means value
type to object type. And while fetching that element in from array list that uh is known as unboxing
as fetching means uh it is converting the object type into value type. So this is the real time example for
boxing and unboxing array list. >> Good. Um can you tell me what is a sync and aait like how does that work
internally? Yeah, as sync and aid are keywords used [snorts] for asynchronous coding inn net.
Async keyword uh defines the method as synchronous method. That means compiler will uh take it as asynchronous method
and whenever the await keyword hits uh compiler uh gets know gets to know that okay this is asynchronous method
and we will we will wait for the uh output for that method but it won't block any thread from operating system
and it will do a remaining process once the return once the value returned from this uh asynchronous method then
remaining steps of that method will execute. So
generally this asynchronous coding means we will use this for DBI uh sorry DB calls and API calls without stopping the
execution it will continue the execution. >> Okay so as we get internally can you
differentiate between task thread and a thread tool? Yeah. Okay. These are the topics behind the asynchronous
programming. Yes. Thread means sorry task first t sorry first thread. Thread is the smallest uh execution unit of
work uh which handles by operating system directly and uh this thread we need to create
manually and we need to manage it. It's like a manual process. Whereas a thread pool thread pool means it is the
precreated pool of threads that operates by net CLR directly means a net uh back end it will
handle it directly without manual intervention and when uh okay
uh it will work this thread pool will work whenever there is an uh unit of work it
won't like it will give that uh thread and it supports like multi-threading means uh at the same time many tasks
will uh complete and coming to task. Task is the abstraction for a thread pool means upon thread pool this task
will work and with this async and await keywords only this task will work. So this is the
highle abstraction for thread pool and in our real time examp real time projects and all we use this task like a
taskr run task dot wait like that >> okay do you know anything about dependency
injection >> yeah this is the important concept uh dependency injection means it's a
design pattern where classes won't create the instances or dependencies internally rather that
it will depend it will take the dependencies from outside. So this is the example for loose coupling.
So with this loose coupling uh we can easily modify and manage the classes like services
and uh this dependency for this dependency injection there is an inbuilt container dependency container we will
uh add our dependencies or services in program CS file and that services we will consume in our controller or
service layer with the constru constructor injection generally. So like this uh dependency injection is
very helpful uh to to achieve loose coupling >> like uh can you give me any scenario
where we use this in your project? >> Yeah. uh in our project uh we use for DB context
without directly uh going to DB from controller we will have this service layer or database data access layers
and not creating instances directly. We will give the we will give the service to dependency container and we will
consume that not only dependency not only DB context we can also inject this repository
patterns. It is very helpful for repository patterns while working with repository patterns.
>> Okay. Um like can you differentiate between abstract class and then interface?
>> Yeah. Abstract class and interface both are used to achieve abstraction in uh C. Abstract class uh the key difference is
when to use which [snorts] abstract class uh contains both concrete methods as well as abstract methods. Whenever we
want a shared shared implementation and a common logic at the time we use this abstract class.
And coming to interface, it is a contract having only method uh declarations. In subasses, we need to
you we need to define the uh methods and to achieve multiple inheritance. We will use the interface
in our projects and all. We use this uh interface as we are implementing repository patterns uh and loose
coupling dependency injection. These interfaces are very helpful for the dependency injection and multiple
inheritance and we will use abstract class also but for shared logic and a common implementation for that kind of
scenarios. >> Okay. Um what is garbage collection?
Yeah, garbage collection in uhn net. It is the automated u cleanup process inn net uh runs by clr common language
runtime. It will it will clean up the unused memories continuously like
uh it will work down based on the generations like there are three generations 0 1 2
uh generation zero whenever there is a variables or objects that lived for short time and are not useful for the
for for further time. So those things will clean up continuously by this garbage collection. And generation two
means whatever the objects survived gen one means generation one and not further using those will clean up by generation
two. And this generation three is like uh global variables or constants and uh some of the catching or logging
things. These things will live up to generation three. >> Like are you explicitly mentioning to
free up the space or is it periodically running the garbage? >> No, it's not a manual process. It is
like automated process. Periodically it will clean up the memory and we can also uh clean up the memory manually but with
the I disposable uh interface methods. uh explain link deferred execution
versus immediate execution. >> Okay. Um yeah, as we discussed earlier
immediate sorry deferred execution means the query will present uh int net but execution won't happens as we iterate
through the collection only it will execute. This is example for innumerable and
whereas immediate execution means uh with the inbuilt methods like two list to array
with this methods after the query at last if we place this methods that query will automatically execute immediately
without any iteration and all. So this uh supported by I queryable. >> Can you differentiate between first
function first or default and single function? >> Yeah. In link you sure
um okay first method will return true sorry will
return the first record after the matching condition. And if no matching condition means it
will throw an exception. And whereas this first or default it will returns the first record after uh matching the
condition. And if no matches are found then it will return null value. So that is the difference between first
and uh first or default. In our project we will use uh first or default for um like
a good coding thing and coming to single method. >> Yeah.
>> What I'm about to ask is which would you ch like choose to use when you expect exactly one record?
>> Exactly one record. Yeah. For that we will use a single method. This single method works whenever only
one uh record needs to match the condition and it will throws the exception for not found like zero
matching or more than one matching. So and to uh avoid this we will there is one
more function like singular default. This will give the um exact one matching condition and uh if more than one or
null means it will give null. Can we start coding question? Yeah, sure.
>> Like can you share your screen and open a notepad or any compiler if you have?
Okay, no problem. I will edit this. Notepad is also fine. >> Yeah, I have a net compiler handy with
me. >> Good. Oh, I'll give you a string. >> Okay.
>> And the string is your name is Arun, right? So the string is my name is Arun. >> I want you to like reverse the words in
that string without using any built-in functions. >> Okay? Like um you want like this. My
name is Arun. >> My name is Arun. So >> and you want should come like
Arun. My sorry Arun is name my
>> you want to uh reverse each word without changing the word >> like without reversing the individual
word you want like this. >> Yeah. >> Okay. Sure.
>> So what's your approach for this? uh my approach for this uh I can do
with the string like I will iterate through each character and whenever there is an empty space
uh I will collect that word And I will store it. Take time to think.
>> Yeah. >> Can I use a split method? >> Um can but can you try without it?
>> Okay, sure. Okay, first I will go through each every character. I will iterate.
>> You can start coding. >> Yeah, sure. Sure. Okay, I will take one.
Before that I need to import system dot
collections dot generic. cannot implicitly convert type string to This will be like you are creating
object for every word. >> Yeah. >> Is that a correct approach?
>> No. >> Okay. If you are struggling to code, you can explain your approach how you will
do. If time passes, we'll see later. Okay, my approach is like I will iterate
each and every word instead of a split method. Um this process will do the split like
whenever the empty um empty character will come that will uh that means each word will uh store in
this words list and later what I will do means I will do the uh reverse manually manual uh reverse string like
for I is equal to this words do.tlength length minus 1 and i - i greater than equal to zero like that
and I can manually reverse each word. So that's my approach but some syntaxes are missing. Sorry.
Let's continue now. >> Yeah, sure.
>> Can we go into .NET Core and web APIs? >> Yeah, sure. >> Can you different between Net Framework
versus .NET Core and the latest .NET 6? >> Yeah, sure. Net uh framework is like legacy Windows
application legacy window application that means it supports only windows
platform and whereas net core is a c it supports crossplatform that means it supports
windows application on Linux operating system as well as Mac OS and there are some more features has
added in net core 6 plus that that has a cloud support means docker support and microservices architecture.
So like that this net was evolved from framework to net R6 plus now we are using net 9 as well.
>> Um can you explain middleware pipeline? Yeah, middleware pipeline in uh net core web API is the combination of software
components that will uh take the HTTP request and process each middleware component and
process it into each middleware component and uh like same it will again uh return the HTTPS response.
So with this middleware we can give some custom logic using use authentication use authorization
and we we can directly map that uh request to endpoint correctly for exact controller using map controller
and add controllers. So with this software components this middleware um was was built
Um do you know any thing about dependency injection like
>> sorry sorry Alan your voice is uh very low. >> Can you hear me now?
>> Yeah. >> So like you know anything about dependency injection life cycle?
>> Yeah. Life cycle methods of dependency injection right? >> Yes.
>> Okay. Yeah. um for every HTTP request like how much time the service instance uh will be
there in the application. For that we use this life cycle scope methods. There are three life cycle life cycle scope
methods are there transient scoped as well as uh singleton. This uh transient means with the add
transient method uh whenever the code request the instance it will create one instance.
Generally for serverless requests with the password related things we use this add transient.
And coming to add scope, it is the most useful uh used in our project. The DB context and repository patterns.
These uh things all present in this ad scoped. And for every HTTP request, it will create an instance and it will be
throughout the HTTP request. And coming to add singleton. This is the um scope which will give the which will
give the uh lifetime sorry which will give the uh scope for uh enter application.
Whenever the application closes the instance the scope will close. For this uh we use in our project like
after catching a logging we use this add add singleton scope method. >> What happens if you inject a scope
service into a singleton >> scope? Yeah, that will give the scope for enter application lifetime.
is web JWT authentication. Can you explain the flow of it? >> Yeah, JSON web token authentication.
It is for a security for security purpose. We use this inn net application.
JWT authentication means uh first client the flow for this one is first client will share the credentials
means username as well as password. The server computes that and once if it is successful
then it will uh issue a token which contains claims nothing but username and password. After that along with that one
key and a role role for that which will be helpful in further authorization and all and this token will shared back to
client that will stored in local session local storage or session storage or cookie
and for next time onwards whenever the client sends an HTTP HTTP request along with that it will share this token as
well. So that with this token uh authorization will happens from next onwards. So this is the JWT
authentication flow. [snorts] Hello
where the token will be stored. Yeah, the token will be stored in front end side
like uh in our application we use ReactJS, right? Uh in our uh project we use that token sorry we
store that token in session storage. >> Can you differentiate authentication and authorization?
Yeah, authentication means who you are. Au authorization means uh what can um what can the role will do means what you
can do. For example, uh when we take in our real real real time project example
if your credentials are present in our DB so that uh if successful login means you
are authenticated person if not you are not you are an invalid person you don't have authentication
and coming to the authorization after that authentication what responsibilities and what uh roles you
can do. For example, if you take admin and a normal user, normal user are authorized
to get all the records like a get method. But whereas admin can do both delete operation, post post operation as
well in insert operation. So these are the differences between authentication and authorization.
What is repository pattern and why do we use it? Yeah, repository pattern means uh it is one um coding style
and it acts a bridge between data access layer as well as DB layer means with entity framework
and uh this with the repository pattern we can use dependency injection and it will achieve loose coupling
that means controller action as well as data access uh layers won't directly uh touch the DB which is like a which
will raise a security c concern. So with this repository pattern we can achieve like a good security and
a good coding style in our projects. >> Any idea on entity framework core? Yeah, entity framework core uh it is an
object relational mapper um which used to provide SQL kind of SQL kind of sorry um with this link with
this uh entity framework core we can use link q link q is a style of writing code like SQL kind of queries in C# objects
itself and also It supports migrations and we can track the database operations as
well with the entity framework core. The main thing is with this entity framework core we can
connect the net uh language with the DT database directly. >> How do you think the repository pattern
and entity framework are related? These are related. We like yeah without this uh repository pattern
we we need to access directly from data access layer to this um DB context means entity framework uh code.
So that's not a good practice and there is a chance to alter the code by user means um some
external parties. But with this repository pattern
the repository pattern is like it is having only interfaces. So it won't exposees the method behaviors and all.
It will show what are the methods available. so that uh it will give good security
among the code. >> What is uh API versioning? >> API versioning.
>> Okay. Yeah. API versioning means if we are adding a
new feature or new changes to our existing API but sometimes our old clients uh will
lose the contact with new one by implementing new features. To avoid this kind of scenarios we will do API
versioning. Generally this API versioning we'll do with URL versioning means we will present the versions
within URL so that the world clients will directly go to the exact version number and so supported users will go to
the versions it will present in controller actions. >> Okay.
>> What is caching in web APIs? Caching means uh storing the we are storing the data
that we are repetitively uh fetching the data from DB or multiple calculations. So uh if we catch that
value then no need to again go to database and all it's like it will for next HTTP request directly it will
provide the data so that the HTTP request process as simply and faster. So this is one of the performance uh
technique optimized technique. Uh where would you implement this caching? Is it in controller service or in the
middleware? >> Caching um not familiar with that. Uh I will go
through it later. >> Can we start SQL? >> Yeah sure.
explain the difference between clustered and nonclustered index. >> Yeah, this clustered uh index and
non-clustered index are to retrieve the data faster in SQL tables. Coming to clustered indexing,
this rel this is related to primary key of a table. Whenever we create one primary key automatically it will create
one clustered index. This clustered index means it physically stores and sorts the data and it will stores the
data in direct uh table directly and whenever we want to filter that based on this clustered index it will directly do
deepsek not a deep scan deepseek. So directly it will give the results. And coming to clustered index
um apart from the primary key for non- primary keys combination of a keys we can prepare this non-clustered index
means for example in our table apart from the ID we want to use every time a name or email or phone number we will
group this columns with um like reusable columns with this non-clustered index then
directly it will helpful to take that uh records. So simply clustered index means uh
deepsek whereas this non-clustered index means it will stores the function pointers
uh not sorry reference pointers to the column names directly. So it won't stores the physical data like a
clustered index. >> Okay. What is normalization and explain its
types? >> Yeah, a normalization is a database design technique
such that we will arrange the tables in we will arrange the large tables into smaller tables so
that it will reduce the redundancy means repeated values and it will avoid duplicate values. And coming to the
types, there are four types. One NF means every column must be atomic value. For example, if user having two numbers,
instead of create instead of inserting that two numbers in single column, we will create a two records. And coming to
2NF, 2 NF sorry 2 NF means the record the table must satisfy one NF as well as no partial dependencies.
Means every non non primary key columns must dependent on primary column and 3NF means
the table must uh follow the 2NF as well as no partial dependencies. Sorry, no transitive dependencies.
That means um yep and boys code and norm NF means it
is the higher level for this 3NF. Yeah, sorry for that interruption. So this is the normalization and its
types. Can you differentiate between delete, truncate and drop?
>> Sorry. Uh can you please repeat it? >> Can you differentiate between delete, truncate and drop?
>> Yeah, sure. These are the uh commands used to delete uh perform delete operation.
delete keyword uh sorry delete uh command used to remove specific rows based on the
condition in a table and whereas this truncate will remove all records without any
specific condition but it will remains the table structure and uh generally the this won't be rolled back
but delete uh command will do roll back in a transaction and drop command
it will removes table structure and uh it will deletes all the rows in a table. We can't roll back uh through
transaction also transaction also for this drop command. So drop is very powerful. We need to be very careful for
using this. Yeah. >> Um and delete and truncate which will be
faster >> delete and truncate. uh truncate will be faster because it will directly remove
all the uh records without any condition checking and all
>> but for delete command will do filtering so that will take a little time when compared to truncate.
>> What is join? Yeah, join in SQL means combining the two or more table data based on the
common column. So, uh there are types of joins like four mainly four types of joints are
there. Inner join, left join, right join as well as uh full join. This left join means
sorry inner join means um it will uh return the records matched in both the tables.
And coming to left join it will return all the left uh table records and no matched values will
uh return as null and same as for right join. But here it will take a right side table and matching values as null from
left side table. And uh full join. Full join means full join means uh it it will return
both the table records and non-matching values as a null. So this is the this is about join.
>> Okay. uh what is stored procedure like how it's uh different from the function? Yeah, stored procedure
is a block of SQL code which uh handles complex business logics and all.
And uh with this stored procedure we can do the CR operation like insert, insert
operation, delete operation, update operation and all. And whereas the function is like a piece
of SQL code which used for reusable purpose and it will return a single value or a table
and this SQL won't perform this cred operations like insert, delete and update. Generally this function will
used in a select query. >> Okay. what is a transaction
and brief about asset properties. Yeah, transaction in SQL means uh
it's like an operation like how the queries executing sorry not how executing
a set of SQL operations that combinely executed as a single unit that is called a transaction
and this transaction we can uh we can track the we can track the SQL query like whether
it is processing or not. How we can track means with this asset properties. There are four properties.
A for atomicity that means all SQL operations should uh should execute or neither will happen.
That means either all or nothing. Nothing should execute. And coming to I. I refers to sorry C. C refers to
consistency. Consistency means um the operation sorry the transaction
>> else you can come up with the real example so you might get the flow. >> Yeah. uh ATM like a bank that is a very
realistic example whenever we are doing the payment sorry can uh this consistency means
Sorry I'm not able to recollect the C property. I will continue with I. Isolation.
Isolation means uh the transactions must be independent of each other means uh neither will interrupt the
other one. And coming to Durability after the completion of the transaction that must be stand very strong like if
any uh DB uh shutdown or uh power off happens
it won't lose the data it won't like come back to the original transaction like that once the transaction marked as
complete it needs to sustain for the further >> okay so the consistency. What you missed
is the system should be in a valid state after any operation. >> Oh, okay.
Yeah, thanks for that. Alakanda, >> what is the indexing like how it impacts the performance?
Yeah, as we um discussed about this indexing earlier with clustered and non-clustered indexes,
we can achieve this indexing. This indexing is a very powerful uh fast approach to retrieve the records
in an SQL table like it will do deep seek rather than scanning the entire table. Based on this
indexes, it directly it will go to the specific column and based on that it will retrieve the records.
Okay. Uh is there any situations that index can make the performance worst?
Index. Yeah, index makes the performance first means one thing I know is like
um after creating the indexes if we are inserting multiple rows means this index also will update.
has to be updated every time. >> Yeah, for every insert. This also needs to update. So that will creates a little
performance lag I guess. >> And also we should be using this only for large tables.
>> Yeah. >> Okay. Can you differentiate between where and having?
>> Yeah. Where and having both are used for filtering for the records. But the key difference with um when they use where
field where uh clause will use without grouping means for filtering uh uh okay before grouping we use this aware
filter and along with this after a group by we use this having clause. Having filter will applies for aggregate
functions as well. >> Can we do a small coding question? >> Yeah, sure.
>> There is an employee table. >> Okay. And the employee table has the employee
name. >> Okay. >> Ro and the salaries.
>> Employee table name salary.
>> His role role and his salary. >> Okay. So now I want a query to find the second
highest salary from the employee table. >> Okay. Find second highest salary. Uh is this query you want write?
>> Yes. >> Okay. Uh we can write this with the two approaches. One is like a simple
subquery and max function. we can get the second highest salary and another approach is with u rank
dense rank for the second highest salary this max method with the subquery will be good
approach but for the nth highest salary that dense rank will be good so I will show you both approaches
first I will write select Max of salary
from employee where salary is less than.
Here we will write the subquery again. Select max Yeah, this is the
query alananda. Now let's see with this using dense rank select.
Look at the salary. Dense rank over order wise salary
as um okay as DR where DR
equals to 2. So this is the code for dense rank alaknanda.
Can you explain this? >> Yeah. uh this is with the dense rank. This is
a window uh function. It will cal it will give the numbering sorry it will order by salary as a
descending. So based on the salaries which is having highest salary it will give the rank one
and if any duplicate also it will give one means for same salary and for the next number it will give directly two.
So this will uh handle the duplicate values as well. So we are taking uh dr equal to two. So that means it will give
the second highest salary. For example, we have 5,000 5,000 5,000 4,000.
>> Okay. Okay. Enough. Enough of that. Enough. >> Yeah. In this case, it will give 4,000.
>> Okay. Good. Yeah. >> Can we go to ReactJS? Yeah, sure.
>> Okay. Why is React faster than the direct DOM manipulation?
>> Yeah. Here comes the role of virtual DOM. What is this virtual DOM means? It is a
lightweight copy for real uh HTML DOM and for every render means every time the re react function react component
changes this virtual DOM will create and it will compare previous virtual DOM and real virtual uh sorry current virtual
DOM with the diffing algorithm. It will track the changes from previous to current one and that uh changed ones
only will apply on a real dome. This is known as reconciliation. So with this process virtual DOM and
reconciliation process ReactJ considered as a first uh application means it will process very fastly.
Can you differentiate between use state and use effect? Yeah, both use state and use effect are hooks in uh react
functional components and use state means it is react functional components or data means a
state in fun class components we use the state and uh use state methods to track the
data inside the component whereas in functional components with this state and set state are combinedly called as
use state hook with that we can manage the functional component data and coming to use effect uh it handles the life
cycle methods means the side effects it handles the side effects of the component functional
component as uh with the dependency array present in use effect it will update the use
effect function generally with this use effect we and call the API calls or DB calls like that.
>> Okay. Can you tell me about controlled and uncontrolled components?
>> Yeah, a control components and uncontrolled components both are used to handle form data
form data of the com uh component. Um whereas control components are handled by use state hook means the
form data handled by use state and this is more suitable and uh maintainable code as if we have many
fields for the form data it would be easy to track with use state whereas uncontrolled components means the form
data handled by DOM objects directly with user ref hook That means uh instead of tracking this uh form data
with the state we will directly assign to direct HTML DOM elements so that it would be faster and but uh it won't
useful for uh larger realtime applications. It will be good for shorter form data.
>> Okay. Props versus state. >> Yeah. Props and uh state both are
components data but props means the data which belongs to parent component that sends to child component consider as
props whereas state means uh the data present inside the component. So uh
yeah this props uh is useful to maintain relationship between parent and child
components whereas the state and uh that props are immutable. We can't change the props from inside a child component and
this uh state can be mutable. That means with whenever the state changes the component will happen rerenders.
Yeah, that's about state and props alandanda. >> Okay. Um what is react life cycle?
>> React life cycle uh yeah previously with the class components we have life cycle methods
like mounting, updating as well as unmounting. Similarly in functional components with
use effect we can achieve this mounting phase means it's like component uh did mount with the use effect empty
dependency array uh it will execute be uh after the mounting phase completes means after the
first render and coming to updating phase which uh relates to component uh did update. That means whenever we are
giving the state variable present in uh whenever we are giving the state variable inside the
dependency error of use effect whenever that value changes the use effect hook will execute that
means it is like component uh did update in class component. And coming to uh unmounting phase,
this can be achieved using a return function inside that use effect. That means it will clear the component.
Sorry, it will clear the logic. >> Okay. Have you used redux?
>> Yeah, we used redux for a global state management in our project. Can you elaborate?
>> Yeah, sure. Um, okay. Redux is like I said, it's a global state management
library. It's similar to context API but if we have more uh if we want to maintain more
state variables in global level means this redux is very helpful rather than context API hook and there are four four
core concepts inside this redux one is store which will stores the state variables global state variables and
second one is uh dispatch this dispatch touch method will present inside the component and it will trigger the
reducer. Reducer will have the uh logic logic as well as the uh store variable name and based on that
logic it will update the global state variable and it will rerender the component. So
this is the flow for redux. >> Okay. Um what is a key in react list? >> Key in react list
uh yeah to handle the JSON or any collections. This key is very important as it
provides the item as well as index of that uh particular uh collection elements. Without this
key, it's hard to maintain the collection data. >> Okay. And what if the keys are not
unique? >> Sorry. Key. >> What if the keys are not unique?
Such that we uh so that we can we cannot uh define exact element what we need to sorry is so that
we can't uh present the exact element which we want to implement. >> So any idea on code splitting?
>> Code splitting. Yeah. Yes. Yes. Code splitting means uh breaking the larger code uh blocks
into smaller ones such that it promotes lazy loading. That means uh it will stop not stops it will first
load the static data which is uh simpler data and expense operations like API calls and
all. It will back means it will uh it will load little sorry how can we say it will take little
time to load that one like lazy loading comes into this place. >> Okay Arun done with my questions.
Yeah, thank you.
The transcript shows a solid, practical understanding of the topics, but includes a few minor inaccuracies. Overall, the candidate's responses are largely correct, with an estimated credibility score of 88 out of 100.
Key inaccuracies include stating the async keyword makes a method synchronous (it actually makes it asynchronous) and referencing a non-existent 'Generation 3' in .NET garbage collection. Additionally, explanations of IEnumerable vs. IQueryable execution models were oversimplified, and some SQL rollback behavior statements were imprecise.
The candidate correctly explained dependency injection lifecycles, the virtual DOM, and ACID properties. These areas demonstrate strong foundational knowledge of .NET and React development.
You can generally trust the claims, as most reflect standard industry knowledge. However, treat the identified inaccuracies (async keyword, garbage collection generations) as areas where the candidate's understanding could be improved.
We compared the candidate's statements against official Microsoft documentation for .NET and C#, as well as widely accepted industry best practices for SQL and React. Each point was cross-referenced to ensure accuracy.
A score of 88 means the interview is highly credible, with only minor errors. It indicates a competent developer who has a few specific areas to refine, but overall provides trustworthy information.
They are unlikely to be deal-breakers for a senior role, as the candidate shows strong practical skills. For a lead or architect position, the nuanced errors might warrant additional technical screening to ensure deep expertise.
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