Practical articles on AI, DevOps, Cloud, Linux, and infrastructure engineering.
Our proxy topped out at 40k connections while the CPU sat half-idle. The bottleneck was kernel defaults tuned for 2009, not the hardware.
Our RAG answers kept citing the wrong paragraph even when the right one was retrieved. A cross-encoder reranker fixed relevance but added 180ms. Here's when that trade pays off.
When a service is slow and every dashboard looks green, bpftrace lets you watch the kernel directly. These one-liners found our tail latency.
The dashboard said the database was fine. It wasn't. Here's how pg_stat_statements found the query eating 40% of our Postgres CPU.
A 900GB events table where every query scanned four years to read one day. Range partitioning by month cut our dashboard queries from 8s to under 200ms.
How we cut auth redirect latency to single-digit milliseconds and ran A/B tests without a flash of wrong content, using Vercel Edge Middleware.
A container with a 2-core limit was pegged at 100% CPU yet running slow. The throttling counter told the real story, and it wasn't the number we set.
A 40GB index on a 6GB table was the first sign. Queries were fine until they weren't. Here's how we found the bloat and cleared it with zero downtime.
We moved a rewrite-heavy request path off Lambda@Edge to Workers and cut p95 from 340ms to 41ms. Here's when that swap pays off and when it doesn't.
Free memory is a lie and load average doesn't see memory stalls. How Pressure Stall Information gives you a direct, early signal of memory contention — and how we wired it into alerts and autoscaling.
The cache-control header most teams under-use. How stale-while-revalidate and stale-if-error turned our CDN from a freshness liability into a latency and resilience win — with the gotchas.
Most CI caches either miss constantly or restore stale junk. The cache-key discipline, scope boundaries, and measurements that turned our pipeline cache from theatre into real minutes saved.
