You could improve in some places. I also use DO and first of all Mastodon itself, the web services, streaming API, can run on minimal nodes. I have almost 1000

You could improve in some places. I also use DO and first of all Mastodon itself, the web services, streaming API, can run on minimal nodes. I have almost 1000 MAU's now and only need about 600M RAM for each web service container instance. And backups, for that I use postgres-operator (yes it's kubernetes), which does S3 backups and those cost almost nothing. (I know cost can go up if I need to restore because of egress traffic) Media is also in S3, with a Cloudfront proxy. As soon as I enabled the CF proxy my S3 costs went down to 0.1 dollars basically. And finally, thank the gods for kubernetes because it allows me to dynamically scale up sidekiq when the queues are backed up. So my base cost for 1000 MAU's on DO is about 150USD/month. But it goes up if Sidekiq scales up temporarily, so it's a fluent final cost based on how many times Sidekiq had to scale up in a month. Most importantly for me is that nothing in this setup is vendor locked. S3 compatible services are plenty, cloudfront web proxy services, plenty of those out there, AWS SES for outgoing e-mails can also be replaced. And of course kubernetes with proper IaC can be deployed into any managed k8s solution.