KPMG .NET Full Stack Interview Questions & Answers
Curated interview practice questions with answers. These are practice scenarios, not a verified list of past interview questions.
About KPMG hiring for .NET Full Stack roles
KPMG is one of the Big Four professional services networks, providing audit, tax and advisory services. KPMG in India and its global delivery centres support clients with technology consulting, data and analytics, risk advisory and cybersecurity. It hires in India for analysts and consultants in data analytics, governance and risk, IT audit, testing and ERP implementation.
For .NET Full Stack roles, this KPMG practice set focuses most on OOP in C# (7), LINQ, Collections and Generics (5), C# Fundamentals (4), SQL Server and T-SQL (4). It has 8 easy, 22 medium questions, so you can start easy and work up to the harder ones.
Company type
Consulting
Headquarters
Amstelveen, Netherlands
Main India offices
Gurugram, Bengaluru, Mumbai, Hyderabad, Pune
KPMG .NET Full Stack interview process
Online assessment or screening test
Technical interview
Managerial or case round
Partner or HR round
Typical pattern based on public candidate experiences. Rounds vary by role, team and year.
Solved for KPMGStart practicing
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An event is a delegate wrapped with restricted access. Outside the class, subscribers can only add or remove handlers with += and -=; they cannot invoke the event or overwrite the whole list with =. This protects the publisher. The standard pattern uses EventHandler<TEventArgs> with sender and args. Remember to unsubscribe long-lived subscriptions, otherwise the publisher keeps subscribers alive and causes memory leaks.
02
You need to remove inactive users from a List<User> while looping through it with foreach, and you get an InvalidOperationException. How do you fix it?
foreach does not allow modifying the collection it is enumerating, so the enumerator throws. The simplest fix is users.RemoveAll(u => !u.IsActive), which is efficient and clear. Alternatives are looping backwards with a for loop and RemoveAt, or building a new filtered list with Where and ToList. For a dictionary, collect keys to remove first, then remove them after the loop.
03
Which design patterns do you commonly see in ASP.NET Core projects?
Dependency Injection is built in. The Repository and Unit of Work patterns wrap data access, although DbContext already implements them. Factory creates objects by type, for example IHttpClientFactory. Strategy swaps algorithms, such as different tax or discount rules, behind one interface. Options pattern binds configuration to classes. Middleware is a Chain of Responsibility, and Mediator libraries implement CQRS by sending commands to handlers.
04
Show a class using a primary constructor with dependency injection.
public class OrderService(IOrderRepository repo, ILogger<OrderService> logger)
{
public async Task<Order?> GetAsync(int id)
{
logger.LogInformation("Fetching order {Id}", id);
return await repo.FindAsync(id);
}
}
Primary constructors on classes arrived in C# 12. Parameters are captured and usable in all members, removing boilerplate fields. They are not readonly, so assign to a readonly field if immutability matters.
05
You are designing a type to hold a 2D point used millions of times in a calculation. Struct or class?
A struct is a good fit because the point is small, logically a single value and created in huge numbers. Structs avoid heap allocation and GC pressure when stored in arrays or locals. Make it a readonly struct so it is immutable and avoids defensive copies. Choose a class instead if the type is large, needs inheritance, or is frequently boxed through interfaces, since copying and boxing remove the benefit.
06
Tell me about a time you made a mistake that affected data, and what you did.
Early in my job (Situation) I ran an UPDATE on a test copy that I believed was staging, but it was a shared QA database, and 2,000 test orders lost their status. My task was to fix it fast. I told my lead immediately, restored the rows from the nightly backup with the DBA, and verified counts. Result: QA lost only an hour. Since then I always wrap manual updates in a transaction and run a SELECT with the same WHERE first.
07
What are your strengths and weaknesses as a developer?
My strength is that I go deep when debugging; I like reading execution plans and logs until I find the real cause, which has helped my team fix slow queries. A weakness was that I spent too long polishing code before asking for feedback. I now open small draft pull requests early and ask for review, which has made me faster and helped me learn from seniors sooner.
08
Your Angular app's first load is slow on mobile because the main bundle is very large. How does lazy loading of routes help?
Lazy loading splits the app into chunks that download only when the user navigates to that route, so the initial bundle is smaller and the first page loads faster, especially on mobile data. In Angular use loadComponent or loadChildren with a dynamic import in the route config; in React use React.lazy with Suspense or the router's lazy option. Angular's @defer blocks can also delay heavy parts of a page.
09
A teammate created a deep inheritance chain Employee > Manager > SeniorManager > RegionalHead to add features. What would you suggest?
Deep hierarchies are fragile: a change in a base class ripples into every child, and behaviours that do not fit the tree get duplicated. I would suggest composition over inheritance. Keep a single Employee entity and give it composed parts such as a Role, an ApprovalPolicy and a list of Permissions, injected as interfaces. New behaviour then means a new policy class, not a new subclass, which is easier to test.
10
An API creates a new HttpClient inside a using block for every outgoing call, and under load you see socket exhaustion errors. How do you fix it?
Disposing HttpClient does not immediately free the underlying socket; connections stay in TIME_WAIT, so thousands of short-lived clients exhaust ports. A single static client fixes that but misses DNS changes. The recommended fix is IHttpClientFactory: register builder.Services.AddHttpClient<PaymentClient>() and inject the typed client. The factory pools and rotates handlers, and you can add resilience with Microsoft.Extensions.Http.Resilience for retries and timeouts.
11
What is the difference between method overloading and method overriding?
Overloading means several methods with the same name but different parameter lists in the same class, resolved at compile time, for example Add(int, int) and Add(double, double). Overriding means a derived class provides a new implementation of a virtual or abstract base method with the same signature, resolved at runtime based on the actual object type. Overloading is compile-time polymorphism; overriding is runtime polymorphism.
12
What is the difference between a stored procedure and a user-defined function?
A stored procedure can perform inserts, updates and deletes, use transactions and TRY-CATCH, return multiple result sets and output parameters, and is called with EXEC. A function must return a value or table, cannot modify database state, and can be used inside SELECT, WHERE and JOIN. Scalar functions used row by row can hurt performance, although SQL Server 2019 and later can inline many of them.
13
Write a BackgroundService that cleans expired OTPs every 5 minutes.
public class OtpCleanupService(IServiceScopeFactory scopes) : BackgroundService
{
protected override async Task ExecuteAsync(CancellationToken ct)
{
using var timer = new PeriodicTimer(TimeSpan.FromMinutes(5));
while (await timer.WaitForNextTickAsync(ct))
{
using var scope = scopes.CreateScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
await db.Otps.Where(o => o.ExpiresAt < DateTime.UtcNow).ExecuteDeleteAsync(ct);
}
}
}
// builder.Services.AddHostedService<OtpCleanupService>();
A scope is created because DbContext is scoped while hosted services are singletons.
A delegate is a type-safe reference to a method with a specific signature, similar to a function pointer but checked by the compiler. You can pass methods as parameters, store them and call them later. Delegates can be multicast, holding several methods that run in order. Lambdas, LINQ, events and callbacks are all built on delegates, and the built-in Func and Action types cover most needs.
15
What is the difference between a shallow copy and a deep copy?
A shallow copy duplicates the object but its reference fields still point to the same child objects; MemberwiseClone and record with-expressions do this. A deep copy duplicates the whole object graph, so changes to the copy never affect the original. Deep copies are usually written by hand or by serialising and deserialising. ICloneable is avoided because it does not say which kind of copy it returns.
ASP.NET Core has a built-in ILogger<T> abstraction injected into any class. You log with levels Trace, Debug, Information, Warning, Error and Critical, and configure minimum levels per category in appsettings.json. Use structured logging with message templates, like logger.LogInformation("Order {OrderId} placed", id), so values become searchable fields. Providers such as Serilog or OpenTelemetry send logs to files, Seq, Elasticsearch or Application Insights.
17
Sort a list of students by marks descending, then by name ascending.
var ranked = students
.OrderByDescending(s => s.Marks)
.ThenBy(s => s.Name)
.ToList();
// in-place alternative with a comparison
students.Sort((a, b) =>
b.Marks != a.Marks ? b.Marks.CompareTo(a.Marks)
: string.Compare(a.Name, b.Name, StringComparison.Ordinal));
OrderBy is stable and returns a new sequence; List.Sort sorts in place and is not stable.
18
A job matches 2 lakh uploaded records against 2 lakh existing IDs using list.Where(x => existingIds.Contains(x.Id)) and takes minutes. What is wrong?
existingIds is a List, so Contains is O(n) and the whole operation becomes O(n x m), around 40 billion comparisons. Convert the IDs to a HashSet<int> first, making each lookup O(1) and the job run in milliseconds. If you also need associated data, build a Dictionary keyed by ID. Always check data structure complexity before parallelising or adding hardware.
19
What are record types and when would you use them?
Records are reference types (or record struct for value types) designed for immutable data. The compiler generates value-based equality, a readable ToString, a deconstructor and support for with-expressions that create a modified copy. A positional record is one line: public record Order(int Id, decimal Total). They suit DTOs, API responses, events and value objects, but not EF Core entities that need change tracking by identity.
20
What is the difference between concurrency and parallelism?
Concurrency means dealing with many tasks at once by interleaving them, for example a web server handling thousands of requests that mostly wait on I/O. Parallelism means doing many computations at the same instant on multiple cores, such as processing an image in four chunks. async/await gives concurrency; Parallel.For and PLINQ give parallelism. A program can be concurrent on a single core but parallel only with multiple cores.
virtual marks a base method as replaceable. override in a derived class replaces it, so calls through a base reference run the derived version. new hides the base method instead: a call through a base reference still runs the base version, and only a derived-type reference sees the new one. Method hiding is usually a sign of a design problem, and the compiler warns when you hide without writing new.
22
Show the newer LINQ methods Chunk, DistinctBy and MaxBy.
// split 1,000 ids into batches of 100 for bulk API calls
foreach (int[] batch in ids.Chunk(100))
await SendBatchAsync(batch);
// unique customers by email
var unique = customers.DistinctBy(c => c.Email).ToList();
// highest-paid employee object, not just the salary
Employee? top = employees.MaxBy(e => e.Salary);
These were added in .NET 6 and remove the need for custom helpers or third-party libraries like MoreLINQ.
23
Show how to bind configuration from appsettings.json using the Options pattern.
// appsettings.json
// "Smtp": { "Host": "smtp.example.com", "Port": 587 }
public class SmtpOptions
{
public string Host { get; set; } = "";
public int Port { get; set; }
}
builder.Services.Configure<SmtpOptions>(builder.Configuration.GetSection("Smtp"));
public class EmailService(IOptions<SmtpOptions> options)
{
private readonly SmtpOptions _smtp = options.Value;
}
appsettings.{Environment}.json and environment variables override base values. Use IOptionsMonitor to pick up changes without restart.
24
Explain eager, lazy and explicit loading in EF Core.
Eager loading fetches related data in the same query using Include and ThenInclude, for example orders with their items. Lazy loading loads a navigation property automatically the first time you access it, requiring proxies and virtual properties; it is convenient but easily causes N+1 queries. Explicit loading loads a navigation on demand with Entry(order).Collection(o => o.Items).LoadAsync(). Projection with Select is often better than all three.
25
What is the difference between a primary key and a unique key in SQL Server?
Both enforce uniqueness. A table can have only one primary key, it cannot contain NULLs, and by default SQL Server creates a clustered index for it. A table can have many unique constraints, each allowing a single NULL in SQL Server, and they create non-clustered indexes by default. Use the primary key for row identity, such as EmployeeId, and unique keys for business rules like a unique email or PAN.
Any() stops as soon as it finds one element, so it is O(1) for most sources, and in EF Core it translates to an efficient SQL EXISTS. Count() may need to walk the entire sequence or run COUNT(*) on the table, which is wasteful just to check for existence. For List<T> or arrays, the Count or Length property is also fine because it is stored, but Any() expresses the intent clearly.
27
What are useMemo and useCallback used for in React?
useMemo caches the result of an expensive calculation and recalculates only when its dependencies change, such as filtering 10,000 rows. useCallback caches a function reference so that a child wrapped in React.memo does not re-render just because a new function was created. Both are optimisations and add complexity, so use them where profiling shows a problem. The React Compiler, stable since late 2025, can apply much of this memoisation automatically.
28
Which HTTP status codes and methods should a REST API use, and what is the difference between PUT and PATCH?
GET reads, POST creates, PUT replaces, PATCH partially updates and DELETE removes. Return 200 OK for success with a body, 201 Created with a Location header after POST, 204 No Content after delete, 400 for invalid input, 401 unauthenticated, 403 forbidden, 404 not found, 409 conflict and 500 for server errors. PUT sends the full resource and is idempotent; PATCH sends only changed fields.
ref passes a variable by reference; it must be initialised before the call and the method can read and change it. out also passes by reference but need not be initialised, and the method must assign it before returning, as in int.TryParse. in passes by reference as read-only, which avoids copying large structs while preventing changes. Overusing ref and out makes code harder to read, so tuples are often cleaner.
30
What is the difference between reactive forms and template-driven forms in Angular?
Template-driven forms are defined mainly in HTML with ngModel and directives; they are quick for simple forms but harder to test. Reactive forms are defined in TypeScript with FormGroup, FormControl and Validators, giving explicit, strongly typed models, easy dynamic fields, custom and async validators, and straightforward unit testing. For enterprise apps such as loan application or KYC forms, reactive forms are the usual choice.
Tips to crack the KPMG .NET Full Stack interview
Learn basics of IT audit, internal controls and risk frameworks, since advisory roles often combine data with governance work.
Practise structured answers for guesstimates and business problems, explaining assumptions clearly step by step.
Prepare examples of working with stakeholders and meeting deadlines, which are common themes in Big Four interviews.
Keep a one-minute story ready for every project on your CV: problem, your part, tools, result.
Practise the hard questions on this page aloud; KPMG interviewers usually ask follow-ups on your first answer.
Frequently asked questions
How many rounds are there in the KPMG .NET Full Stack interview?
Candidates usually go through 4 stages: Online assessment or screening test; Technical interview; Managerial or case round; Partner or HR round. The exact rounds change with the role, team, location and your experience, so confirm the process with the recruiter.
Which topics should I prepare for the KPMG .NET Full Stack interview?
This practice set leans on OOP in C# (7), LINQ, Collections and Generics (5), C# Fundamentals (4), SQL Server and T-SQL (4). Revise those first, then practise explaining one or two of your own projects end to end, because most KPMG interviewers ask you to walk through real work.
Are these the exact questions asked at KPMG?
No. These are curated practice questions that match the skills and difficulty usually tested in consulting interviews like KPMG's. They are not a leaked or verified list of past questions.
Where does KPMG hire .NET Full Stack professionals in India?
KPMG has large teams in Gurugram, Bengaluru, Mumbai, Hyderabad, Pune. Openings and locations change often, so check the KPMG careers page and filter by city and experience.