Use RDS. SQLite only works if you have one persistent machine with a disk and file system.
The problem with AWS lambda and SQLite are 1) network file systems often don’t support the APIs that SQLite needs to implement concurrent access; SQLite is not a database server 2) local storage for AWS lambda is ephemeral, your DB will be deleted, and if there’s two lambdas, they won’t be using the same DB.
Just use one EC2 instance and SQLite, or lambda with RDS.
The problem with AWS lambda and SQLite are 1) network file systems often don’t support the APIs that SQLite needs to implement concurrent access; SQLite is not a database server 2) local storage for AWS lambda is ephemeral, your DB will be deleted, and if there’s two lambdas, they won’t be using the same DB.
Just use one EC2 instance and SQLite, or lambda with RDS.