Technical screening questions
Ask for one example per question and listen for specifics.
- Embed or reference in MongoDB? A good answer: Access patterns and document size.
- How do you structure Express routes? A good answer: Routers, middleware and validation.
- How do you do authentication? A good answer: JWT or sessions and refresh handling.
- How do you manage state in React? A good answer: Context or a store.
- How do you deploy a MERN app? A good answer: Build, environment config and hosting.
Quick screening questions
Use these when you have only a few minutes.
- How do you model data in MongoDB for a one-to-many relationship?
- How do you structure an Express API?
- How do you handle authentication across React and the API?
What separates the levels
Match the level to the requirement before you submit.
- Junior: builds components and routes.
- Mid: owns features.
- Senior: designs the architecture.
Red flags
Any of these is a reason to probe further.
- Tutorial apps only.
- Cannot explain indexes.
- No auth experience.
Tools you should hear mentioned
A MERN stack developer with real experience usually names several of these without prompting.
- MongoDB
- Express
- React
- Node.js
- JWT or OAuth
- Docker
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 MERN 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.