I've used serverless for the past 3 years in production. Unfortunately my experience with it is that it's several orders of magnitude more expensive than a k3s cluster on a cheap provider like Hetzner, and it's slower.

When I last calculated the cost of serverless, it was ~500-5,000x more expensive for the compute compared to k3s and ~10x more expensive for bandwidth at a minimum. To me, removing the burden of maintaining infra didn't justify that level of cost.

Some examples:

- Upstash latency was ~70ms for Redis. Cost was prohibitive.

- AWS Lambda / Cloudflare Worker / Firebase Function cost becomes prohibitive. At least cold starts aren't as bad as they used to be.

- Firebase Realtime Database performance didn't scale, and wound up getting maxed out because of the way it works with nested key updates. Replaced with a Redis instance in k3s which is now running at <2% max capacity and is ~1,000x cheaper.

- Tried Planetscale. Cost was much higher than PostgreSQL.

- Tried Vercel. Bandwidth costs are very scary ($400 / TB egress, or ~350x the cost of Hetzner if you don't count Hetzner's free 20 TB per node)

That being said, I don't know of any good, reasonably-priced GPU offerings.