FerretDB is an open source document database that provides MongoDB compatibility to other database backends like Postgres and SQLite. It allows developers to use familiar MongoDB features, syntax, and commands for various use cases. In this guide, we covered running FerretDB locally via Docker, testing the connection with mongosh and the MongoDB Node.js client, and deploying it to Fly.io for a production-ready setup. We also discussed how to insert documents into FerretDB, update document records, inspect JSONB data in the Supabase Dashboard, and deploy to Fly.io. Overall, FerretDB offers flexibility by enabling MongoDB workloads on Postgres and SQLite, allowing developers to avoid vendor lock-in while maintaining control over their data architecture.