Clear, practical essays on how real software gets designed, breaks, and ships — the failure modes I've run into, the trade-offs that turned out to matter, and the patterns that hold up in production.
An UPDATE-heavy table that's barely touched by readers was somehow generating index bloat and burning IO. The fix wasn't more indexes or a faster disk. It was understanding HOT updates and one storage parameter almost nobody sets: fillfactor.
HTTP/2 multiplexes streams over one connection, so people assume one slow response can't block the others. It can, just one layer down, in TCP. Here is the head-of-line blocking that survived HTTP/2 and why HTTP/3 had to abandon TCP entirely to kill it.
Before you reach for Kafka or SQS, Postgres can be a correct, exactly-once-ish job queue — if you know SKIP LOCKED. Here is why the naive queue table deadlocks under load and the one clause that fixes it.
Connection exhaustion under load almost never means you ran out of memory — it means you ran out of ephemeral ports to TIME_WAIT sockets. Here is the TCP lifecycle that explains it and the fixes that actually work.
A trace is a tree of spans stitched together by a context that has to ride along every hop. The traces that break almost always break at a boundary where nobody propagated the headers. Here is the model.
A session is a pointer to server state; a JWT is the state itself, signed. That single difference decides revocation, scaling, and where your security holes live. The trade-off, honestly told.
A VPC is just a CIDR block, a subnet is an AZ plus a slice of it, and "public" is a fact about a route table — not a checkbox. Here is the mental model that makes connectivity bugs obvious.
Readiness gates traffic, liveness restarts containers, startup protects slow boots — and wiring them up the same way is how a slow dependency turns into a restart loop. The differences that matter.
A test that passes on retry is not fixed — it's lying. The five real causes of flakiness, how to diagnose each one, and why auto-retry is a last resort, not a strategy.
Each topic page collects every article on that subject.