Edge key-value store vs. origin DB lookup: a Bogotá app localizes fast

Edge key-value store vs. origin DB lookup: a Bogotá app localizes fast
An app did feature-flag and geo-config lookups by calling its origin database on every request. A user in Bogotá hit the edge, then waited on a 130ms round trip to the origin DB just to learn which banner to show.
That lookup gated rendering, so it sat on the critical path for every page.
They moved the config — a few kilobytes, changing rarely — into the CDN's edge key-value store, replicated to every PoP. The lookup now resolved locally at the Bogotá edge in under 2ms.
Config-lookup latency dropped from 130ms to 1.5ms. Origin DB query load fell by millions of reads a day.
Origin DB wins for large, frequently-written, relational data. Edge KV wins for small, read-heavy, rarely-changing config on the hot path.
The number that mattered: config lookup from 130ms to 1.5ms.