micro1 API Developer Interview: REST Design, API Security and Rate Limiting

micro1's API developer interview stays close to the HTTP layer: how you shape endpoints, who gets to call them, and what happens when ten times the expected traffic shows up. This guide is preparation for micro1's AI interview with Zara for the API Developer role; Labeling Jobs is not affiliated with micro1. micro1 publishes a list of common API developer interview questions, and security alone accounts for several of them. The themes below cover what those API developer interview questions check.

Every micro1 interview is a spoken conversation with Zara, micro1's AI interviewer. How it runs, what proctoring involves and what happens afterwards are in our Zara interview guide, and you can rehearse with micro1's mock interview tool.

REST API design and backward compatibility

Zara wants to hear design rules you can defend. Talk about resource-oriented URLs, using HTTP methods and status codes for what they mean, consistent naming, pagination for large collections and documentation generated from an OpenAPI spec. Then the harder half: changing an API that clients already depend on. Explain your versioning scheme (URL path or header), additive changes as the default, deprecation notices with a sunset date, and contract tests that catch a breaking change before release. A weak answer says "we just add v2" with no plan for the clients still on v1.

Authentication, authorization and API security

This is the heaviest theme. Separate authentication from authorization early, because interviewers notice when candidates blur them. Explain when OAuth2 with delegated scopes fits, what a JWT carries and why short expiry and key rotation matter, and where plain API keys are acceptable. Cover role-based access checks on every request, input validation and parameterised queries against injection, CORS configured to specific origins, and why CSRF matters mostly when browsers send cookies. A good closing point is what you push to an API gateway (auth, TLS termination, request limits) versus what stays in the service.

Performance, caching and serialization

For high-traffic APIs, walk through where time goes: database queries, payload size, serialization, network hops. Mention caching with sensible invalidation, connection pooling, async processing for slow work, compression, and letting clients request only the fields they need. Binary formats such as Protocol Buffers are worth raising for internal services. Saying "add more servers" before measuring anything is the answer that loses ground.

Rate limiting and production monitoring

Explain token bucket or leaky bucket limits, per-client quotas, returning 429 with a Retry-After header, and where the limiter lives. On monitoring, describe structured logs with request IDs, dashboards for latency percentiles and error rates, alerts with thresholds that do not page people for noise, and audit logs for sensitive calls.

Backend work on Labeling Jobs

Three listings on Labeling Jobs have backend or API in the title, all from micro1: Backend C#/.NET Developer and Backend Java Developer at $60–110/hr, and Senior Backend Engineer at $50–100/hr. They are AI training projects for experienced engineers rather than product roles. More are under software and IT. Figures checked on 4 October 2026.