If this were viable, why would it not have worked before?

Because something wasn't in place to make it work. There are millions of examples where the second mover won, often because the first mover was too early, or the tech wasn't there to make it work, or the market didn't understand the value, etc.

In this case I imagine there are three massive benefits that you'd have over being the first mover:

- AWS is more mature and therefore moving slower, so it's easier to keep up.

- AI is useful for building 80% working code, so there's a lot less to do to keep up.

- There's a lot of devs looking for ways to move off Localstack due to the price change, which gives you (potentially) a pool of willing volunteers to contribute to an OSS alternative.

You can also learn from Localstack's open source version about what's needed, what works, what doesn't work, etc.

Personally, I would get value out of really solid compatibility of the base features of a few core services (sqs, s3, kms, and maybe dynamo are the main ones that come to mind) with a light weight gui interface and persistence.

If I’m getting into esoteric features or some “big” features that don’t make sense locally, then I just spin up a real dev account of aws, so I know I’m getting the real experience.

Hello! We won't have the broad coverage that Localstack has... we're not aiming to be the "next Localstack"... just want to keep the core services that were available for free in the LS community up to date. If you’re looking for larger services like MWAA, sorry, but we won't be supporting them.... Most core AWS services don't receive many updates anyway (their APIs don’t change drastically or frequently)

That's true if you assume making these things is manual work. But of course with well documented API service and AI coding tools, making a functional local equivalent of any given service is not all that hard.

"LocalStack was just a mess of a codebase" - very true.

I do think there's potential to semi-automatically create a compatible suite of services, but it'll require some very talented use of LLMs and some novel testing approaches. Not something I want to sign up for.

I evaluated Floci, but that has the typical issues you'd expected with freshly minted vibe code.

I suppose (among many other things) LLMs are changing this. We no longer need that many contributors when we can use AWS docs, intercept AWS API calls and give it to AI agent to mimic. Of course, contributors are still needed for maintaining tests and validations.