Leaving serverless led to performance improvement and a simplified architecture

Why's that? Serverless is just the generic name for CGI-like technologies, and CGI is exactly how classical web application were typically deployed historically, until Rails became such a large beast that it was too slow to continue using CGI, and thus running your application as a server to work around that problem in Rails pushed it to become the norm across the industry — at least until serverless became cool again.

Making your application the server is what is more complex with more moving parts. CGI was so much simpler, albeit with the performance tradeoff.

Perhaps certain implementations make things needlessly complex, but it is not clear why you think serverless must fundamentally be that way.

I think cause connections can be reused more often. Cloud flare workers are really prone to doing a lot of TLS handshakes cause they spin up new ones constantly

Right now were just hang aws far hate for the go servers, so there really isn’t much maintenance at all. We’ll be moving that into eks soon though cause we are starting to add more stuff and need k8s anyways

With standard Go servers, self-hosting becomes trivial:"

A key point that I always make. Serverless is good if you want a simple periodic task to run intermittently without worrying about a full time server. The moment things get more complex than that (which in real world it almost always is), you need a proper server.

Have the users upload to s3 directly and then they can either POST you what they uploaded or you can find some other means of correlating the input (eg: files in s3 are prefixed with the request id or something)

I agree this is annoying and maybe I’ve been in AWS ecosystem for too long.

However having an API that accepts an unbounded amount of data is a good recipe for DoS attacks, I suppose the 100MB is outdated as internet has gotten faster but eventually we do need some limit

That said, as an example, an m8g.8xlarge gives you 32 vCPU / 128 GiB RAM for about $1000/month in us-east-1 for current on-demand pricing, and that drops to just under $700 if you can do a 1-year RI. I’m guessing this application isn’t super memory-heavy, so you could save even more by switching to the c-family: same vCPU, half the RAM.

Stick two of those behind a load balancer, and you have more compute than a lot of places actually need.

Or, if you have anything resembling PMF, spend $10K or so on a few used servers and put them into some good colo providers. They’ll do hardware replacement for you (for a fee).