Free tier is super limited and super easy to accidentally break out of. I had a single file in S3, but because my logging settings were wrong, I broke the free tier with junk logs.

The t2 micro ec2 instances are fine, but you need to be very careful about their storage and network egress.

Best use I've had for AWS that has managed to stay within the free limits has been Lambda. Managed to convert a couple self hosted discord bots to a few Lambda functions, works great. Plugging it into CloudFormation and tying up CI/CD with CodePipeline and the like were overkill but good learning exp.

I don't think there's any ECS free tier, but you can fit a private container repository in the free S3 limits as well.

You don't mention what services yiu plan to utilize and the limits are different for each.

Try it all. Keep good notes.

Some service names are marginally misleading, but understanding what it does and how it bills does two thing: Helps you avoid overbilling; and also ensures you “get” it.

Properly secured and understood, S3 + immutable saves my ass more than o once because could prove that as of x bi-hourly backup, PG reflected some given status.

In other words, “I did not fuck that specific thing up, and as of the last time I was in good faith awake, it looked like x. Let’s look at logs/code, bc last I saw it, it mapped perfectly to reality.”

The bit about “keep good notes,” above, is for future you.

“Oh yeah I played with that random AWS service a few years back, wish I could recall the outcome,” vs “Mind giving g me a sec to have a look at my notes, I’ve seen this before!”

That translates to execs as “Yep, I follow, and u have ref material from the last n times I solved this problem, so I’m your guy, I just need a sec to locate the details of the last round before I straight up commit to an answer.”

Definitely set a CloudWatch alert to notify you if the cost goes above a certain limit. And make sure you check that email regularly. It takes a small misconfiguration to rack up a hefty bill. Best to catch it early.

Other suggestion is to stay away from the console or command line. Learn how to use CloudFormation or, much better, the CDK. You can set up a full serverless application stack, run it for a while, then delete the whole thing so it won't accidentally incur extra charges. It's also a good practice so you can include the stack setup code with the rest of your code.

Stick to open standard stuff. Retooling sticks and they hope to tar you in those services so you find yourself paying