Technical screening questions
Ask for one example per question and listen for specifics.
- Walk me through a feature you built from database to UI. A good answer: Look for ownership of schema, API contract and UI state, not just one layer.
- How do you handle authentication across the front end and API? A good answer: Token storage trade-offs, refresh flow and session expiry.
- How do you keep an API and client in sync as requirements change? A good answer: Versioning, shared types or OpenAPI contracts.
- What would you do if a page is slow? A good answer: Separate front-end rendering from API and query time and measure each.
- How do you decide between SQL and NoSQL? A good answer: Data shape, consistency needs and query patterns.
Quick screening questions
Use these when you have only a few minutes.
- Which side of the stack is your strongest, and which did you learn on the job?
- How do you manage state in a large front end?
- Describe a feature you took from database to UI.
What separates the levels
Match the level to the requirement before you submit.
- Junior: builds components and simple endpoints.
- Mid: delivers a feature across the stack.
- Senior: designs the system, sets conventions and mentors.
Red flags
Any of these is a reason to probe further.
- Strong on one layer and vague on the other.
- Lists many frameworks with no shipped project.
- No testing practice.
Tools you should hear mentioned
A full stack developer with real experience usually names several of these without prompting.
- React or Angular
- Node.js or a server framework
- REST or GraphQL
- PostgreSQL or MongoDB
- Git
- CI/CD
Run the call well
Ask for the last project first, then dig into the second or third question. Take notes on versions, team size and outcomes, and record them with the submission so the vendor’s later technical interview does not surprise you.
Frequently asked questions
How long should a full stack developer screening call take?
Fifteen to twenty minutes is enough to cover the project, three technical questions and availability, rate and work authorization.
Do recruiters need to know the technology?
Working vocabulary is enough. Use the sourcing guide for the role and listen for specifics instead of judging technical depth yourself.