What are common sources of memory leaks in Go services?

0-2 years experience

1. 1You added an HTTP handler that reads the request body into a byte slice but never lets the slice go out of scope. What effect could that have on memory over time?
2. 2If you launch a new goroutine for each incoming request and never signal it to stop, how might that show up in the service's memory usage?
3. 3What happens if you defer a file.Close() inside a tight loop that processes thousands of files?

2-5 years experience

1. 1After deploying a feature that uses sync.Pool, the service's memory keeps growing. Walk me through how you'd investigate whether the pool is leaking.
2. 2During a load test you see many large slices retaining old data. Explain how slice capacity can cause a leak and how you'd fix it.
3. 3A goroutine got stuck waiting on a channel forever. How would that manifest as a memory leak and what steps would you take to prevent it?

5-8 years experience

1. 1Design a monitoring strategy for a high‑traffic Go microservice to detect and alert on memory leaks caused by goroutine or resource leaks. Which metrics and tools would you include?
2. 2When migrating a monolith to multiple Go services, you need to ensure that legacy C libraries used via cgo don’t leak memory. How would you audit and mitigate such leaks at scale?
3. 3Explain the trade‑offs of using runtime.SetFinalizer versus explicit Close methods for managing external resources in a large Go codebase.

8+ years experience

1. 1Our organization runs dozens of Go services and sees intermittent OOM crashes due to subtle leaks. Propose an organization‑wide policy and tooling pipeline to catch leaks early, covering code review, static analysis, CI, and production observability.
2. 2We plan to refactor a critical service to use a custom memory allocator for performance gains. How would you evaluate the risk of introducing leaks, and what safeguards would you put in place across teams?