The Node (and more) Banter

The Hidden Cost of Async Context in Node.js (with Bryan English)

From background tasks to cross-request tracing, many developers rely on async context to glue state across their code. But under the hood? It’s fragile, unpredictable, and often a performance landmine.

In this episode, we’re joined by Bryan English to dive into the lesser-known tradeoffs of async context management in Node.js—and how to build observability without breaking your app or your brain.

We’ll dig into:

✅ What async context really is (and what it isn’t)

✅ Why it breaks in production, especially under load

✅ The performance overhead of AsyncLocalStorage

✅ Real-world patterns for context propagation that don’t implode

✅ Lessons from building observability tools on top of it all

If you've ever struggled to trace a request, debug a memory leak, or just wondered why your context vanished mid-flight—this one’s for you.