Data Quality, Contracts & ObservabilityThe Airbnb quality arc, contracts from discourse to production, validation frameworks, and SLOs for data.The most editorially distinctive cohort — data contracts are the debate this newsletter helped shape. Production anchors: Airbnb's Wall→Quality-Score arc, Uber's operational excellence program, Meta's Table Compare, GoCardless and Whatnot shipping contracts for real.Week 2: Data contracts in productionFrom discourse to deployment: what a contract contains beyond schema, where it's enforced, and what changes organizationally when producers own their data.

Figure 1 — a data contract and its enforcement points. By the end of this week you can read this as a prediction: which schema change gets caught where, and whose build fails

A product team renames customer_id to account_id in their service database — a routine refactor, reviewed and shipped. That night your pipeline runs green and quietly fills a revenue-critical field with NULLs. The producer team learns your pipeline *exists* during Thursday's incident review. Here's the question that decides everything downstream: whose bug is that? Nobody signed anything. Nobody broke anything they'd promised. There was no promise.This week is about installing the promise: what a data contract actually contains, where it's enforced, and — the part the discourse skipped — what made adoption succeed at the companies that shipped it.After this week you canThe full week 2 brief is part of LeetData Pro.Case studies

GoCardless — Data Contracts at GoCardless — 6 Months On

GoCardless — 3 Things Our Software Engineers Love About Data Contracts

Whatnot — Data Contracts in the Modern Data Stack

Adidas — Adidas Data Mesh Journey - Sharing data efficiently at scale

Grab — Real-time data quality monitoring Kafka stream contracts with syntactic and semantic test.

Ternary Data — Data Contracts & Domain Ownership w/ Ananth Packkildurai

Exercises

The Silent Schema Break

Week 2 check: Data Contracts

The Poison-Pill Message