Question bank

Interview questions, with guidance on how to answer

834 questions across 64 roles. Open one to see what a strong answer includes and common slips, then drill it out loud with Ava. New to answer structure? Start with the learning hub.

572 questions match your filters.

TechnicalEntry levelBackend Engineer
If you were building an API for a simple to-do app, what endpoints would you create, and how would you handle errors?
Tests: API design
TechnicalEntry levelBackend Engineer
How do you protect a web application from someone sending malicious input, such as an SQL injection attack?
Tests: Security fundamentals
TechnicalMid levelBackend Engineer
An endpoint starts timing out in production at peak hours. How would you investigate, and what would you look at first?
Tests: Reliability & observability
TechnicalMid levelBackend Engineer
How do you handle two requests trying to update the same record at the same time?
Tests: Performance & concurrency
TechnicalMid levelBackend Engineer
How do you evolve an API that other teams depend on without breaking them?
Tests: API design
TechnicalMid levelBackend Engineer
How do you handle secrets like database passwords and access keys in your services?
Tests: Security fundamentals
TechnicalSeniorBackend Engineer
When would you split a monolith into separate services, and when would you argue against it?
Tests: Distributed systems & scalability
TechnicalSeniorBackend Engineer
How do you decide what to alert on for a service you own, so the on-call engineer is woken only for things that matter?
Tests: Reliability & observability
TechnicalEntry levelFull-Stack Engineer
Walk me through how you would build a page that shows a list of items from a server, including what the user sees while it loads.
Tests: Frontend development
TechnicalEntry levelFull-Stack Engineer
What happens, step by step, when a user submits a sign-up form on a website, from the browser all the way to the database?
Tests: Backend & API development
TechnicalEntry levelFull-Stack Engineer
If you were storing users, their posts and comments on those posts, how would you set up the tables and relationships?
Tests: Data modelling & databases
TechnicalMid levelFull-Stack Engineer
Tell me about a feature you built from the database all the way to the user interface. What decisions did you make along the way?
Tests: End-to-end feature delivery
TechnicalMid levelFull-Stack Engineer
A user reports that saving their profile sometimes fails with no error message. How would you figure out whether it's a frontend or backend problem?
Tests: Testing & debugging across the stack
TechnicalMid levelFull-Stack Engineer
How do your changes usually get from your machine to production, and what checks happen along the way?
Tests: Deployment & cloud basics
TechnicalMid levelFull-Stack Engineer
How do you handle authentication in a web app, and where do you store the user's session or token?
Tests: Backend & API development
TechnicalMid levelFull-Stack Engineer
How do you keep the frontend's data in sync with the server, for example right after a user edits something?
Tests: Frontend development
TechnicalSeniorFull-Stack Engineer
You're asked to deliver a large feature in six weeks with a small team. How would you break it down and decide what ships first?
Tests: End-to-end feature delivery
TechnicalSeniorFull-Stack Engineer
How would you roll out a risky change, like a new checkout flow, so you catch problems before every user sees it?
Tests: Deployment & cloud basics
TechnicalEntry levelMobile Engineer
Can you explain the lifecycle of a screen in an iOS or Android app, and why it matters when you load data?
Tests: Platform fundamentals
TechnicalEntry levelMobile Engineer
How do you make sure your app's screens adapt to different screen sizes, dark mode and larger text settings?
Tests: Mobile UI & app architecture