Stateful Apps for Thousands of Users: Horizontal Scaling, Session Affinity, and Sharding in Databricks Apps

Databricks Apps make it easy to stand up a powerful internal app, but most teams don’t have a clear mental model for what happens when usage jumps from a handful of users to hundreds or thousands. In this advanced, under-the-hood session, we’ll walk through how Databricks Apps can remain stateful at scale: horizontal scaling across multiple app instances, session affinity to keep user context and in-memory state attached to the right replica, and sharding to distribute traffic and load safely across your fleet.

By the end, you’ll have a practical architecture playbook and checklist you can apply to take an existing Databricks App—from LLM agents to analytics UIs—and harden it for real production scale without giving up the fast developer experience you already enjoy.