[Glench]

I've been using SQLite/Litestream for https://extensionpay.com for about 3 years now! Serves about 120m requests per month (most of those are cached and don't hit the db), but it's been great!

I was convinced that SQLite could be a viable db option from this great post about it called Consider SQLite: https://blog.wesleyac.com/posts/consider-sqlite

Using SQLite with Litestream helped me to launch the site quickly without having to pay for or configure/manage a db server, especially when I didn't know if the site would make any money and didn't have any personal experience with running production databases. Litestream streams to blackblaze b2 for literally $0 per month which is great. I already had a backblaze account for personal backups and it was easy to just add b2 storage. I've never had to restore from backup so far.

There's a pleasing operational simplicity in this setup — one $14 DigitalOcean droplet serves my entire app (single-threaded still!) and it's been easy to scale vertically by just upgrading the server to the next tier when I started pushing the limits of a droplet (or doing some obvious SQLite config optimizations). DigitalOcean's "premium" intel and amd droplets use NVMe drives which seem to be especially good with SQLite.

One downside of using SQLite is that there's just not as much community knowledge about using and tuning it for web applications. For example, I'm using it with SvelteKit and there's not much written online about deploying multi-threaded SvelteKit apps with SQLite. Also, not many example configs to learn from. By far the biggest performance improvement I found was turning on memory mapping for SQLite.

[knur]

How do you deploy updates of your app without downtime? (I know not all web apps need that but in case you do I would love to know about your approach)

[Glench]

I don't! I take the moment of downtime. It's usually instant — only as long as it takes to stop and restart the server. Occasionally a DB migration will take longer — the longest I've so far was 10-15 seconds — and the site is down for that time. I think this is acceptable, but it would be nice to have a more seamless automated solution.