coreweave·Software Engineer·Technical Phone Screen·Senior

Senior

May 2026

Summary

Phone screen for a Production Engineer role at CoreWeave. The whole thing was a practical terminal exercise, no theory, just spin something up and make it work. Pretty refreshing compared to the usual leetcode grind.

Questions Asked (1)

Start an HTTP server from the terminal, write a program to query one of its endpoints, parse the response to identify relevant machines, then send HTTP POST requests to mark those machines as offline.

API & IntegrationsSystem DesignTechnical Trade-offs

Author's notes

This is a full mini-task disguised as a single question.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the requirements and constraints, then outline a step-by-step plan covering server setup, client implementation, response parsing, and POST requests. Emphasize robust error handling, idempotency, and scalability considerations, and discuss trade-offs between simplicity and production-readiness.

Pro tip: Mention idempotency and retry logic for the POST requests to avoid marking machines offline multiple times, and use environment variables or config files for endpoint URLs to make the solution portable.

1. Clarify Requirements and Constraints

Ask about the server technology, response format (JSON/XML), authentication, rate limits, and expected scale. Confirm whether the server is local or remote and if the POST requests need to be idempotent.

2. Start the HTTP Server

Use a simple command like `python -m http.server` or `npx http-server` to start a local server, or describe starting a custom server if the endpoint is predefined. Mention binding to a specific port and handling CORS if needed.

3. Write the Client Program

Choose a language and HTTP library (e.g., Python requests, Node.js axios). Implement a GET request to the endpoint, parse the response (e.g., JSON), and extract machine identifiers based on a defined schema.

4. Send POST Requests to Mark Machines Offline

For each machine, send a POST request to the appropriate endpoint with the machine ID and offline status. Use concurrency (e.g., async/await, thread pool) if many machines, and handle errors with retries and backoff.

5. Validate and Monitor

Log results, verify that machines are marked offline (e.g., by re-querying), and discuss monitoring/alerting for failures. Mention idempotency keys to prevent duplicate updates.

Key Points to Mention

HTTP methods (GET vs POST) and status codes (200, 404, 500)
Parsing JSON/XML responses and handling malformed data
Idempotency and retry logic with exponential backoff
Concurrency and rate limiting for scalability
Error handling and logging for observability
Configuration management (environment variables, config files)

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.