I doubt you can have a writable filesystem with any server less offering. Serverless offerings force you to have all your state network accessible so that they

I doubt you can have a writable filesystem with any server less offering. Serverless offerings force you to have all your state network accessible so that they can offer you horizontal scalability by using load balancers - so no writable+persistable file system that SQLite needs. What I do is use a normal VM on GCP, run my docker container on that, and write to a regionally replicated disk (so it is copied between zones on every write). Snapshots run hourly and are stored in GCP storage. This gets you high reliability (if you can have a few mins down time to reboot) but not horizontal scalability.