Viktor Nikolaiev's blog

A follow-up to the timeout middleware post.

Sometimes we need concurrent processing that preserves input order while streaming.

After a decade of Go backends, I wanted to try something different – so I built a daily number-picking game with vintage UI and game theory elements.

I needed a longer timeout for a single file upload endpoint, and the obvious fix – wrapping the route in another timeout middleware – silently did nothing.

Imagine updating a user's last_active_at timestamp on every HTTP request – thousands of tiny UPDATEs per second, perfect for batching, except each call only sees one user ID at a time.

File upload handlers often stream the request body straight to S3, so there's nothing buffered to validate.

Concurrent one-off scripts need progress visibility, but Grafana is overkill and a pile of atomic counters with fmt.Printf is barely readable.

I was cleaning up a large GCS bucket when I discovered that listing the files, not deleting them, was the real bottleneck – list APIs are paginated and strictly sequential, 1000 files per request.