--- title: "Full-stack developer interview questions | Orbit" description: "What full-stack developer interviews usually test, the usual stages, and 17 practice questions with what a good answer covers. Practise free in the warm-up." canonical: https://orbitanswer.com/roles/full-stack-developer last_reviewed: 2026-10-18 --- [Companies](https://orbitanswer.com/companies) [Roles](https://orbitanswer.com/roles) [Free warm-up](https://orbitanswer.com/warmup) - [Home](https://orbitanswer.com/) - [Roles](https://orbitanswer.com/roles) - Full-stack developer Role interview guide # Full-stack developer interview questions and what to expect Full-stack developer interviews usually check that you can build a feature end to end: a working interface, the API behind it and the database underneath. Candidates commonly report a take-home or live exercise building a small app, then questions on JavaScript or the role's main language, databases and deployment; experienced candidates are often asked to design a whole feature. What candidates commonly report; it varies by employer, level and country. Last reviewed 18 October 2026. [Practise a full-stack developer mock interview](https://orbitanswer.com/register) [Warm up free on these questions](https://orbitanswer.com/warmup?track=role%3Afull-stack-developer) ## The usual stages - 1 Recruiter or HR screen - 2 Take-home or online test: often a small app with a frontend, an API and a database - 3 Technical interview: walk through your code, then extend or fix it live - 4 Fundamentals across the stack: JavaScript, a framework, APIs, databases and deployment - 5 Feature or system design for experienced roles - 6 Hiring manager or behavioural round ## What interviewers check - Building something that works end to end, not just one layer - Knowing where logic belongs: browser, server or database - Sound data modelling and API design - Security basics on both sides: validation, authentication and secrets - Getting code deployed and running, not only working locally - Pragmatism: choosing simple tools and shipping ## Behavioral questions ### Tell me about a time you delivered a feature on your own across frontend and backend under a deadline. A good answer covers - The scope, and what you cut to make the deadline - How you split the work between screens, API and data - What shipped and what you cleaned up afterwards ### Describe a bug that turned out to be in a different layer from where you first looked. A good answer covers - The symptom and where you first looked - How you traced it across the browser, network, server and database - The real cause and what it taught you about debugging ### Tell me about a time you had to learn a new framework or tool quickly for a project. A good answer covers - Why it was needed and how much time you had - How you learned: the docs, a small prototype, someone experienced - What you built, and what you'd do differently ### Tell me about a time you pushed back on a feature request or suggested a simpler way to do it. A good answer covers - The request and the cost you saw in it - The simpler option and how you made the case - The outcome for users and the team ## Questions about the job ### Walk me through an app you've built: the stack, how data flows from a click to the database, and why you chose each part. A good answer covers - A short picture of the frontend, API, database and hosting - One request traced from the click to the database and back - A choice you'd make differently now, and why ### Talk me through how you'd build a simple notes app with login, from the database tables up to the screens. A good answer covers - Tables or collections for users and notes, with each note tied to its owner - API endpoints that check the user is logged in and owns the note on every request - Screens with loading and error states, and how it gets deployed ### Where should input validation happen: in the browser, on the server, or both? Why? A good answer covers - The browser for quick feedback to users - The server because anything sent from a client can be changed - Database constraints as a last line of defence ### How does a login session work across the frontend and backend? Compare cookies and tokens. A good answer covers - Server-side sessions with a cookie versus self-contained signed tokens - Where tokens are stored and the risks of each: cross-site scripting, CSRF - Expiry, logout and refreshing a session ### What is CORS, and why might a request work from Postman or curl but fail from the browser? A good answer covers - The browser's same-origin rule, and what CORS headers allow - Preflight requests for some methods and headers - Fixing it on the server by allowing the right origins, not a wildcard everywhere ### In a MERN-style app, when would you use MongoDB, and when would a relational database be the better choice? A good answer covers - Documents suit nested data that's read together; relational suits many relationships and joins - Consistency needs, such as orders and payments - Explaining the choice you made in your own project ### How do you deploy a full-stack app, and how do you keep secrets such as API keys out of the code? A good answer covers - A build step, hosting for the frontend and the API, and a managed database - Environment variables or a secrets manager, never committed to Git - Separate settings for development, staging and production ### A list page gets slow once there are thousands of records. What would you change across the stack? A good answer covers - Pagination or infinite scroll instead of loading everything - An index for the query, and returning only the fields the page needs - Caching, and a loading state so the page feels responsive ### How would you add live updates, such as chat messages or order status, to an existing web app? A good answer covers - Polling, server-sent events and WebSockets, and when each fits - Reconnecting, and messages that arrive late or out of order - Making it work with more than one server ### When an API changes, how do you keep the frontend and backend in step? A good answer covers - Shared types or an API schema, and versioning - Tests that check the API contract - Changing in steps so older clients keep working ### Talk me through how you'd let users upload and display a profile photo safely. A good answer covers - Checking file type and size on the server, not just in the browser - Storing files in object storage rather than the database, and serving them through a CDN - Resizing images, and controlling who can see them ## Motivation and fit ### Do you see yourself leaning more towards frontend or backend over time? Why? A good answer covers - An honest answer, with an example of work you enjoyed - Why knowing the whole stack still helps in that direction - What you're learning now ### Why do you want to work here as a full-stack developer? A good answer covers - Something specific about the product or its users - How your experience fits the stack the team uses - What you'd hope to own in your first year ## Tips - Treat a take-home like work you'd ship: a README, clear setup steps, a few tests and a note on what you'd do with more time. - Expect to change your take-home live; know your own code well enough to extend it without searching. - Have a deployed project with a live link; it shows you can get past 'works on my machine'. - Say which layer you're talking about as you answer; full-stack answers get muddled quickly otherwise. - Don't list every technology you've touched; pick the stack you know best and be ready to go deep on it. ## Practise it out loud A mock interview asks what full-stack developer interviews usually test, follows up on your answers and gives you a report. The warm-up is free, needs no account and checks five of these questions as you answer. [Practise a full-stack developer mock interview](https://orbitanswer.com/register) [Warm up free on these questions](https://orbitanswer.com/warmup?track=role%3Afull-stack-developer) ## About this guide Written by Orbit from what candidates and interviewers commonly describe for this kind of job. The questions are Orbit's own practice questions, not questions taken from any employer's interviews. Processes change, so check the job post and what your recruiter tells you. ## Company guides to read with this one - [BrowserStack BrowserStack runs a cloud testing platform that lets teams test websites and apps on real browsers and devices, and it describes itself as remote-first. 14 practice questions](https://orbitanswer.com/companies/browserstack) - [Adobe Adobe's careers site describes a call with a Talent Partner, an interview with the hiring manager, then skills assessments and team interviews: coding… 14 practice questions](https://orbitanswer.com/companies/adobe) - [Accenture For freshers in India, candidates commonly report online cognitive, technical and coding assessments and a spoken-English communication test, followed by one… 14 practice questions](https://orbitanswer.com/companies/accenture) - [CRED Candidates commonly report that CRED's engineering interviews include problem-solving and machine coding or design rounds, followed by conversations about how… 13 practice questions](https://orbitanswer.com/companies/cred) ## More guides: software engineering - [Mobile developer Mobile developer interviews usually go deep on one platform (Android with Kotlin, iOS with Swift, or a cross-platform framework such as Flutter or React… 17 practice questions](https://orbitanswer.com/roles/mobile-developer) - [QA engineer QA and test engineer interviews usually test how you think about what could go wrong: writing test cases for an everyday feature, reporting a bug clearly and… 17 practice questions](https://orbitanswer.com/roles/qa-engineer) - [Software engineer Software engineer interviews usually combine coding (solving a problem out loud, often in a shared editor), computer science fundamentals and a discussion of… 17 practice questions](https://orbitanswer.com/roles/software-engineer) - [Backend developer Backend developer interviews usually focus on APIs, databases and how a service behaves under load or failure, alongside coding in the role's main language… 17 practice questions](https://orbitanswer.com/roles/backend-developer) - [Cybersecurity analyst Cybersecurity analyst interviews usually test networking and operating-system basics, common attacks, and how you'd respond to an alert or incident. 17 practice questions](https://orbitanswer.com/roles/cybersecurity-analyst) - [DevOps engineer DevOps and site reliability interviews usually cover Linux, networking, CI/CD, containers and at least one cloud platform, and lean heavily on… 18 practice questions](https://orbitanswer.com/roles/devops-engineer) [All 32 role guides](https://orbitanswer.com/roles) [Guides by company](https://orbitanswer.com/companies)