Do you regret choosing serverless (lambda) architecture?

No. But the applications were all ideal cases, such as

* route/transform messages from one message queue to another

* process email bounces

* sign up/unsubscribe/verify email subscribers

It is can be a hassle to host that kind of service on an EC2 instance; try to lowball the size of your server and you might find the $5 a month server got overwhelmed, started swapping, and ran up your EBS bill by $200 a month.

Lambda functions are scalable down to very light workloads and also to very high workloads. That's important because large services often have obscure functions that run occasionally, or small services sometimes get a crazy high workload.

In those cases Lambda has your back.

Not at all! It's been great for work that I would traditionally use a cron job for. It's _amazing_ when combined with API Gateway. An API that I use every day (upload photos or emails of receipts with metadata into Expensify) is built entirely on Lambda + API Gateway. It works great and costs me almost nothing.

Nope, it's allowed me to scale from an itch-scratching side-project to hundreds of users for cents per month in usage costs.

It'll probably require a rewrite at the millions of users level, but it works for now.

It's been great for hosting smaller ML models for the cost. Kinda loses its usability on larger models though.

No, I don't. It was a super fast way to deploy an API. It is Active-Active, it is cheap, and it gets the job done.

I think it’s a great fit for web APIs, as long as you have a means for distributed concurrency control.

Yes I did.