A builder’s guide to scaling Databricks Apps

This guide outlines scaling Databricks Apps across four stages—design, build, test and deploy, and operate—starting with agreed latency and peak-load targets before any code is written. It recommends keeping app compute for serving the UI, sending heavy work to purpose-built services, using async code, splitting soft and hard state so sessions can be rebuilt on any instance, and letting load tests and telemetry determine instance size, worker count and instance count. It also covers connection budgeting for Lakebase, graceful shutdown within the 15-second SIGTERM window, and monitoring and alerting in production.