// Hacker Noon · 26 January 2026

Why “Obvious” Performance Optimizations Often Backfire: Lessons From Systems Serving 50M+ Requests

Theoretical optimizations can backfire in practice. We learned this the hard way at DoorDash when a "smart" HashMap change made latency worse. After years optimizing 50M+ monthly requests, here's what actually works: measure tail latencies not averages, layer your caching with jittered TTLs, profile...

Hacker Noon

@hacker-noon · Ujjwal Gulecha

hackernoon.com

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