Practical articles on AI, DevOps, Cloud, Linux, and infrastructure engineering.
The edge is fast because it's constrained. This is the decision map for what belongs at the edge, what belongs at origin, and how compute, data, caching, and auth fit together.
Edge code runs in hundreds of PoPs, lives for milliseconds, and gives you no shell. Here's how we get logs, traces, and metrics out of it anyway.
Verifying signed tokens at the edge with WebCrypto blocks bad traffic early and saves a full origin hop. Here's the pattern we ship, and the traps.
A request leaving a laptop somehow lands on a server 20ms away. Here is what actually decides which point of presence answers.
Edge functions run everywhere and remember nothing. Durable Objects give you one addressable, single-threaded instance with transactional storage — the missing source of truth.
Buffered SSR makes users wait for the slowest query before they see anything. Streaming from the edge flips that — send the shell now, fill the gaps as data lands.
Edge runtimes look like Node but aren't. Here's what actually breaks — CPU caps, no filesystem, no TCP sockets — and how we route around it.
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.
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.
Both put SQLite near your users, but they solve replication and write latency very differently. We ran the same schema on both for a month and picked one.
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.
Edge compute is useless without an edge data layer. Three serverless databases that put data within ms of your edge functions, with the tradeoffs that aren't on the marketing pages.
