Interview prep
Backend Developer interview questions
13 questions backend developers get asked, grouped by type. Under each one are the skills it is really testing, so you can pick a story from your own work that shows them.
Technical
- How do you change a database column used by a live table without causing downtime?Tests: database design, system design
- Walk me through how you'd diagnose a query that suddenly got slow in production.Tests: debugging, database design
- How do you change an API's response shape without breaking the clients already calling it?Tests: api design, system design
- Two services need to stay in sync after an action, such as an order being placed and inventory being updated. How do you handle the case where one update succeeds and the other fails?Tests: system design, reliability
- How do you design a background job so it can safely run twice if it's accidentally triggered again?Tests: system design, reliability
Situational
- A single client is hammering your API and degrading service for everyone else. What do you do?Tests: reliability, system design
- A downstream service goes down and your service starts retrying failed calls aggressively, making things worse. How do you prevent that?Tests: reliability, system design
- You discover a database credential was accidentally committed to the repository history. What do you do?Tests: security, ownership
Behavioral
- Tell me about a time you disagreed with a coworker and how you handled it.Tests: conflict resolution, communication
- Describe a project or task that did not go well and what you did about it.Tests: ownership, reflection
- Give an example of persuading someone to adopt an idea they initially resisted.Tests: influence, communication
- Walk me through how you decided what to work on when you had more requests than time.Tests: prioritisation, judgment
- Tell me about a time you had to learn something new quickly to get a job done.Tests: learning agility, ownership
Getting the resume right first? See resume guidance for Backend Developers, or browse interview questions for every role.