6 euro hetzner box with compose or fly.io for a side project doing 30 req/s VPS Setup

At 30 req/s and one person, take the VPS. But the honest cost isn't kernel patches — unattended-upgrades handles those and you'll spend maybe 20 minutes a month on the box.

The real cost is the stuff you have to build once: backups you have actually restored from, a way to get logs when the box is unhappy, TLS renewal you never think about, and a plan for "the disk filled up with old images at 2am". Call it a solid weekend up front, then close to nothing.

The thing that would change my answer is the database. Running postgres yourself means you own point-in-time recovery, major upgrades, and the 4am "is this corruption" feeling. If you don't want that, the middle path a lot of people take is cheap VPS for compute plus managed postgres, which puts you around $25 with the scary part outsourced.

30 req/s is nothing — a CX22 will serve that with the CPU mostly idle. You aren't choosing on capacity, you're choosing what you want to be responsible for at 3am.

One thing people overweight in the Fly column: multi-region and machine suspend are genuinely nice, and they solve problems you don't have. One region, one box, 30 req/s, one person. Buy the simple thing.

Take the VPS but write the setup down as it happens. Not ansible, not terraform — a SETUP.md where every command you ran is pasted in order. When the box dies in 14 months, that file is the difference between an afternoon and a lost weekend.

I've rebuilt from mine twice. It's 60 lines and it's the highest-value file in the repo.

Watch egress on the uploads. 40 GB sitting in R2 is fine — no egress fee is the entire reason to use it. But if you serve those files through your API rather than direct from R2, you pay for that traffic on the VPS side. Hetzner's included traffic is generous but not infinite, and it's an easy thing to not notice until the overage line appears. Signed URLs straight to R2, always.

Counter-view on the 6x: it's about $300 a year in absolute terms. If the project makes any money at all, that's noise and the real question is where your attention goes. If it makes nothing, $300 is real money and the VPS is obviously right. You already know which of those you're in.

fly cold starts will bite you on a low traffic side project — machines suspend and the first request eats a second or two. the vps is always warm