LiteFS, a distributed SQLite database, was initially developed to distribute data geographically for faster response times. However, during the development process, the creators discovered an unexpected use for LiteFS: replacing the API layer between services with SQLite databases. Instead of designing and building a complex API, the entire database is shipped to the client, allowing them to query and join data using SQL. This approach eliminates the need to consider different use cases and access patterns of consuming services. While there are trade-offs, such as limitations in updates and stricter contracts, shipping read-only replicas can provide flexibility and power in certain use cases.
https://fly.io/blog/skip-the-api/