#DevtoRedis

I measured eight Redis rate limiter designs in 3,853 trials. Check-then-act let 29% too much through, WATCH refused up to 42% of good traffic, and caller clocks broke token buckets.

Redis 8.4 adds IFEQ, IFNE, IFDEQ and IFDNE to SET. I measured a 1MB compare-and-set drop from about 4.3ms to 1.6ms using the new digest option, then found the official Python client silently drops the server's own GET reply on one code path.

How Duong Phuc Khanh (Kido) replaced bloated relational habit logs with 46-byte Redis/Valkey Bitmaps and CPU hardware POPCNT instructions, dropping p99 streak latency from 140ms to 0.08ms.

The Eras Tour presale hit 3.5B requests, 4x Ticketmaster's prior peak. Work the interview design: waiting room, atomic Redis seat holds, expiry, payment.

Explore Redis for caching, rate limiting, sessions, coordination, messaging, and background jobs,...

I wrote 10,000 keys into Redis running in Docker, then ran one ordinary Docker command and counted...

in a SaaS billing service we hit a sudden spike every time a new plan rolled out – the API surged...

If you've used standalone Redis and then switched to Redis Cluster, you may have encountered this...

Three plans declare a concurrent login cap of 2, 3 and 3. The middleware falls back to 3 when Redis has no key, and only a Stripe event ever writes the key, so the trial value is reachable only by cancelling a paid plan.

Why a job lock should be a renewed lease rather than a timeout on the work, what a cancelled run does to a TTL set to the worst-case runtime, and giving "I did nothing" its own status code.

Cache-aside, write-through, TTLs, stampedes and stale data. How senior engineers design caching that stays correct under load.