All sections
Subjects are the browse hierarchy. Round type, seniority, and difficulty are filters applied on top, because a single question is often relevant to several roles and several kinds of round at once.
Data Structures & Algorithms
21 questionsCoding-round questions organised by the pattern they test rather than by problem name, so you learn transferable techniques instead of memorising individual puzzles.
- Arrays & Strings2
- Hashing & Maps1
- Two Pointers & Sliding Window2
- Linked Lists1
- Stacks & Queues1
- Trees & BSTs2
- Graphs2
- Heaps & Priority Queues1
- Dynamic Programming2
- Greedy Algorithms1
- Recursion & Backtracking1
- Sorting & Searching1
- Intervals1
- Bit Manipulation1
- Tries & Advanced Strings1
- Complexity Analysis1
Latest in DSA
- How do you decide between BFS and DFS - and how do you recognise a graph problem that nobody described as a graph?
- Given package weights in a fixed order, find the smallest ship capacity that delivers them all within D days
- Count the subarrays whose elements sum to k, where the values may be negative.
System Design
17 questionsOpen-ended design rounds broken into the building blocks they draw on, plus full case studies worked end to end with explicit trade-off reasoning.
Low-Level Design & OOD
12 questionsObject-oriented design rounds where you produce classes, interfaces, and interactions rather than infrastructure boxes and arrows.
- OOP Principles1
- SOLID & Design Heuristics2
- Creational Patterns2
- Structural Patterns1
- Behavioural Patterns2
- Concurrency in Design2
- Machine Coding Rounds2
Latest in LLD
- Adapter, decorator and facade - what concrete problem does each one solve, and where would reaching for it be over-engineering?
- How would you design a thread-safe component, and why is adding synchronized to every method not a design?
- Where does encapsulation or polymorphism change a design, and how do you decide between composition and inheritance?
Backend Engineering
12 questionsLanguage-agnostic service engineering: the protocols, boundaries, and failure handling that sit between a coding round and a full system design round.
- HTTP & REST2
- Authentication & Authorisation2
- Microservices2
- Resilience Patterns2
- GraphQL & gRPC1
- Distributed Systems Theory1
- Backend Scenarios2
Latest in Backend
- A dependency that normally answers in 80ms starts taking eight seconds. What in your service reacts, and in what order?
- The same domain has to be exposed to a mobile app, a partner integration and internal service-to-service traffic. Where does GraphQL fit, where does gRPC, and where does neither?
- Consumer lag on your orders topic climbs every morning and never clears before the next peak. Work through it.
Java & Spring
15 questionsLanguage and framework depth for JVM roles, covering the internals that separate framework users from engineers who understand what runs underneath.
- Core Java2
- Collections Framework2
- Concurrency & Multithreading2
- JVM Internals & Tuning2
- Streams & Functional Java1
- Modern Java Features1
- Spring Core1
- Spring Boot1
- Spring Data & JPA2
- Testing on the JVM1
Latest in Java
Python
12 questionsPython for backend, automation, and data roles, including the runtime behaviour that surprises candidates who only know the syntax.
- Core Python2
- OOP in Python2
- Decorators, Generators & Iterators1
- Concurrency & the GIL2
- Python Memory & Performance1
- Django & FastAPI2
- Testing in Python2
Latest in Python
- If you were writing a small value type in Python, which dunder methods would you implement, what would you let a dataclass generate, and how does super() decide what to call?
- Your test still reaches the network even though you patched the client. Talk me through fixture scope, parametrisation, and where a patch has to point.
- What does the GIL actually prevent, and how do you decide between threads, processes, and asyncio?
Node.js & TypeScript
10 questionsServer-side JavaScript depth, where nearly every question eventually reduces to understanding the event loop and the type system.
.NET & C#
10 questionsC# language semantics and ASP.NET Core service internals for Microsoft-stack interviews.
Latest in .NET
- How does the .NET garbage collector decide what to collect, and how would you make a hot path allocate less?
- What is the difference between a value type and a reference type in C#, and what do nullable reference types guarantee?
- A client disconnects but your server keeps working on their request. How does cancellation actually propagate in .NET?
Go
8 questionsGo for infrastructure and high-throughput services, where concurrency idioms carry most of the interview weight.
Latest in Go
- How do you tell whether a value escapes to the heap, and how would you find the allocations that are costing you?
- How do goroutines leak, and how would you find a leak in a running service?
- Your function returns nil on the success path, the caller checks err != nil, and the check fires anyway. What happened?
Frontend Engineering
14 questionsBrowser-platform depth, framework reasoning, and the frontend-specific design round that full-stack candidates are least prepared for.
- JavaScript Core2
- TypeScript2
- React2
- Angular & Vue1
- Browser & Rendering1
- Web Performance2
- CSS & Layout1
- Accessibility2
- Frontend System Design1
Latest in Frontend
- Angular, Vue and React are answers to the same problems. Compare how each handles change detection, reactivity and dependency injection.
- How do you decide between flexbox and grid, and why does z-index so often not do what you expect?
- Design the frontend for a data-heavy operational dashboard with live updates.
Databases & SQL
13 questionsQuery-writing rounds and the storage-engine reasoning behind why a query is slow, for backend, data, and DBA roles alike.
- SQL Query Writing2
- Indexing2
- Transactions & Isolation2
- Query Optimisation2
- Data Modelling2
- NoSQL Stores1
- PostgreSQL Internals1
- DBA & Operations1
Latest in Databases
- Adding a second LEFT JOIN doubled the revenue figure on a report. Explain what happened and write the correct query.
- How do you choose between a document store, a key-value store, a wide-column store and a graph database for a new service?
- Three queries hit the same table with different filters. What composite indexes do you build, and how do you order the columns?
DevOps & Cloud
13 questionsPlatform and infrastructure questions for DevOps, SRE, and any backend role expected to own its service in production.
QA & Testing
18 questionsThe full QA spectrum kept deliberately separate: manual craft, automation engineering, and performance testing are different interviews with different rubrics.
- Testing Fundamentals2
- Manual & Functional Testing1
- Test Strategy & Planning2
- Automation Fundamentals2
- Selenium & WebDriver1
- Playwright & Cypress1
- API Testing2
- Performance Testing1
- Performance Analysis & Tuning1
- Mobile Testing1
- SDET Coding Rounds1
- QA in CI/CD2
- QA Scenarios1
Latest in QA
- What does auto-waiting do in Playwright and Cypress, how do the two differ architecturally, and what can neither of them test?
- Two teams own two services that talk to each other. How do you stop one breaking the other without running both together in a shared environment?
- A test that has passed for a year starts failing after a refactor that was supposed to change nothing. Is it a bug or a bad test?
Data & AI Engineering
13 questionsQuestions for data engineering, ML engineering, and the LLM-application roles now appearing in mainstream hiring loops.
CS Fundamentals
11 questionsThe core-subject rounds common in campus hiring and still used to probe depth in experienced interviews.
- Operating Systems2
- Computer Networks2
- DBMS Theory2
- OOP Theory2
- Compilers & Runtimes1
- Security Fundamentals2
Latest in CS Core
- What are the four pillars of OOP, and what is the difference between abstraction and encapsulation?
- Take this table to third normal form, then tell me when you would deliberately denormalise — and what does ACID guarantee?
- Walk me through what happens between the source you write and the instructions the CPU runs, and where does a JIT fit into that?
Architecture & Tech Leadership
12 questionsRounds specific to senior, staff, principal, and architect titles, where the subject is judgement and organisational impact rather than code.
- Architecture Trade-offs2
- Quality Attributes & NFRs2
- Documentation & ADRs2
- Migration & Modernisation1
- Cost & Efficiency1
- Technical Strategy2
- Architecture Scenarios2
Latest in Architecture
- How do you decide whether to build a capability in-house or buy it?
- The business says the system must be highly available. How do you turn that into a number, and what does that number cost?
- Every architecture document you have inherited is out of date. How do you write documentation that survives contact with a changing system?
Business Analysis
14 questionsRequirements craft for BA and functional-consultant roles, where the interview tests elicitation and precision rather than technology.
- Requirements Elicitation2
- Documentation & Artefacts2
- Process & Data Modelling2
- The BA in Agile2
- Stakeholder Management2
- Analysis & UAT2
- BA Scenarios2
Latest in BA
- You are mapping data from a legacy system into a replacement and the two define a customer differently. How do you work that out?
- The business insists on a requirement that nobody can test — "the system must be intuitive". What do you write instead?
- A stakeholder says the new request is not a change, it is just a clarification. How do you handle that?
Product Management
14 questionsThe PM loop as it is actually run: product sense, analytical, execution, and strategy rounds, each with its own scoring rubric.
Presales & Solutioning
14 questionsSolution-engineering and presales-architect interviews, which uniquely test commercial instinct and live communication alongside technical depth.
- Discovery & Qualification2
- Solution Design & Proposals2
- RFP & RFI Response2
- Demos & POCs2
- Estimation & Commercials2
- Objection & Competitor Handling2
- Presales Scenarios2
Latest in Presales
- In the room, the customer tells you a competitor has committed to something you cannot match. How do you respond?
- The bid is due in five days, three technical sections are unanswered and the clarification window has closed. How do you run the last five days?
- You have been handed a scope and a budget, and the budget cannot buy the scope. What do you put in front of the customer?
Engineering Management
12 questionsThe EM loop, which mixes people scenarios, delivery judgement, and enough retained technical credibility to lead engineers.
Agile, Scrum & Delivery
14 questionsScrum master, agile coach, and delivery-manager interviews, where framework recall gets you screened in and scenario judgement gets you hired.
Behavioural & Culture Fit
13 questionsThe round candidates most often under-prepare, treated as a skill with structure rather than small talk, including the rubric interviewers score against.
HR, Screening & Offer
12 questionsThe recruiter and HR rounds that gate the technical loop and decide your compensation, where most candidates improvise and lose money.
Working in a Domain
6 questionsDomain knowledge as a skill rather than as a subject: why it decides between two technically equal candidates, how the vocabulary gates entry, and how to acquire it deliberately instead of absorbing it over a decade.
Latest in Domain Skills
- Everyone in the business calls it the fax queue, and nothing has been faxed since 2014. Do you keep that name in the code?
- The domain expert tells you one thing and the written procedure says another. How do you work out which one the system should follow?
- The operations team says there is no rule for this, they just use judgement. How do you model that?
Banking & Financial Services
16 questionsHow a bank works underneath the app: the ledger that must always balance, the rails money moves over, the identity and financial-crime controls wrapped around it, and the regulatory reporting that constrains every design decision.
- Core Banking & Accounts2
- Lending & Credit1
- Payments & Rails2
- Cards & Acquiring1
- KYC & Customer Onboarding2
- AML & Financial Crime2
- CLM & Customer Lifecycle1
- Risk & Capital1
- Regulatory Reporting1
- Reconciliation & Settlement2
- Open Banking & APIs1
Latest in Banking
- How would you aggregate exposure across a portfolio so that the number can still be defended a year later?
- Walk me through what happens between a customer tapping a card and the merchant getting paid.
- If payments settle around the clock, what does end of day mean and which day does a transaction belong to?
Capital Markets
14 questionsTrading, clearing and settlement systems, where correctness is measured in audit trails and the constraints are latency, determinism and an immovable settlement calendar.
- Order Lifecycle2
- Market Data2
- Clearing & Settlement2
- Custody & Asset Servicing2
- Risk & Margin2
- Post-trade Processing2
- Execution & Algorithms2
Latest in Capital Markets
- The clearing house has called far more initial margin than your own risk system predicted. How do you find out why before the deadline?
- You need one consolidated best bid and offer across five venues whose feeds arrive at different latencies. How do you build it, and what will it get wrong?
- A corporate action is confirmed with an effective date in the past, after you have already struck positions and sent statements. How does your system cope?
Insurance
12 questionsPolicy and claim systems, where the engineering difficulty is product configurability and time: effective dates, retroactive change, and a record that must be reconstructable as at any past instant.
- Policy Administration2
- Underwriting & Rating2
- Claims Lifecycle2
- Insurance Fraud1
- Actuarial & Reserving2
- Reinsurance2
- Distribution & Channels1
Latest in Insurance
Healthcare & Life Sciences
12 questionsClinical and payer systems, where the record is legally significant, interoperability is decades of overlapping standards, and interrupting a clinician has a real cost.
- Patient Records & Identity2
- Interoperability Standards2
- Clinical Workflows2
- Coding & Billing2
- Claims & Payers2
- Privacy & Security in Health1
- Life Sciences & Trials1
Latest in Healthcare
- You are building the payer side. How do you configure benefits so a plan change does not need a code release?
- Take me through what a payer does with a claim after you submit it, and how you keep denials from piling up.
- Follow an order through to its result, then design an alert on that pathway that clinicians will not learn to dismiss.
E-commerce & Retail
14 questionsThe path from browse to delivered and back again, where inventory is the central consistency problem and every edge case is a real order belonging to a real person.
- Catalogue & Product Data2
- Search & Discovery2
- Cart & Checkout2
- Inventory & Availability1
- Order Management & Fulfilment1
- Pricing & Promotions2
- Payments & Fraud1
- Returns & Reverse Logistics2
- Marketplace & Omnichannel1
Latest in E-commerce
- A customer returns one item from a three-item order paid partly by gift card. How much do you refund and to what?
- Design the returns flow properly, from the customer pressing the button to the money and the stock landing back where they belong.
- Design the checkout flow for a marketplace with multiple sellers per order.
Logistics & Supply Chain
12 questionsSystems that model the physical world, where recorded state diverges from reality by default and reconciliation is continuous rather than exceptional.
Telecom
12 questionsOperator systems either side of the OSS/BSS line: provisioning a service on a network, and turning its usage into money.
- Subscriber & Provisioning2
- Network Inventory2
- Mediation & Rating2
- Billing & Revenue Assurance2
- OSS/BSS Architecture2
- Network Services & 5G2
Latest in Telecom
- The monthly bill run dies two thirds of the way through and the cycle closes tomorrow. What do you do?
- A family plan shares 100 GB across five SIMs with each SIM capped at 30 GB. How does charging enforce both limits at once?
- A subscriber's service is working on the network but no subscription exists in billing. How did that happen, and what do you do about it?
Manufacturing & Industrial IoT
14 questionsPlant and shop-floor systems, where the OT/IT boundary is a hard constraint and a bad deploy can stop a production line.
- Shop-floor Systems2
- OT/IT Integration2
- Industrial Protocols2
- Telemetry & Time Series2
- Predictive Maintenance2
- Quality & Traceability2
- Safety & Availability2
Latest in Manufacturing
- A dashboard has been showing the same temperature for two days and nobody noticed. Walk the path and tell me what would have caught it.
- A customer returns three failed units built in different weeks. You have one shift to say what else is affected. How do you bound it?
- A critical vulnerability is published for software running on a plant segment that will not be patched for nine months. What do you do in the meantime?
Regulation & Compliance
10 questionsThe rules that reach into system design across every industry, and the difference between having a control, implementing it, and being able to evidence it.
- Data Privacy2
- Data Residency & Transfers2
- Auditability & Evidence2
- Access Control & Separation of Duties2
- Standards & Certification2
Latest in Compliance
- Your data is pinned per region, but login must be globally unique and admins want one global search. How do you build that?
- A legal hold lands on Friday afternoon and your nightly deletion jobs run at two. What do you do, and what do you build afterwards?
- Fraud and AML say keep it for years, privacy says delete it. How do you build a system that satisfies both?