1 min lesson
What happens at each hop
Take this case and make the call: "Which layer carries the JD's mandate to 'optimize the raw/bronze layer for performance, reliability and cost at TB-to-PB scale,' and why is its file layout so consequential?"
Step 1 of 2
What happens at each hopthe transforms that earn the layer
- 1Land to bronze. Write incoming events append-only with idempotent keys; do not parse or reshape beyond what's needed to store them durably. This is the replay buffer for everything downstream.
- 2Promote to silver. Deduplicate on event keys, enforce and cast the schema, drop or quarantine malformed rows and conform identifiers so a
user_idmeans the same thing across sources. - 3Build gold. Aggregate into business marts or engineer agent/ML features from silver - narrow tables shaped for one query pattern, rebuildable from silver at any time.
The JD's "optimize the raw/bronze data layer for performance, reliability and cost at TB-to-PB scale" lives at the first hop. Bronze is where billions of events a day actually land, so its file layout and write path decide whether the rest of the platform is cheap or expensive to read.