concurrency - Abrarqasim Blogs

FastAPI Async in 2026: The def vs async def Choice I Keep Getting Right

In FastAPI, async def is a promise not a superpower. Here's the def vs async def rule I use, the incident that taught me the…

Rayyan | July 17, 2026 | 8 min

Backend

Golang Concurrency Patterns 2026: errgroup and Context I Actually Ship

The Go concurrency patterns I actually reach for in 2026: errgroup instead of sync.WaitGroup, context cancellation everywhere, worker pools without cargo cult.

Rayyan | July 4, 2026 | 8 min

Go

Go Concurrency Patterns in 2026: What Go 1.25 Let Me Delete

Go 1.25 added WaitGroup.Go and a stable testing/synctest. Here are the Go concurrency patterns I actually use in 2026, and the boilerplate I deleted.

Rayyan | May 24, 2026 | 9 min

Go

Rust vs Go in 2026: How I Actually Choose

I've shipped production services in both Rust and Go. Here's the decision framework I actually use, with code, honest trade-offs, and no benchmark wars.

Rayyan | May 23, 2026 | 9 min

Backend

Go Iterators: Six Months of range Over Functions in Real Code

I ignored Go 1.23 iterators for almost a year. Here's what finally made me reach for them, where they're worth it, and the footgun that…

Rayyan | May 4, 2026 | 8 min