I had a horrible time with Localstack. It's very similar to AWS but not exactly the same, so you hit all kinds of annoying edges and subtle bugs or differences and you're basically just doing multi-cloud at that point. The same kinds of problems you encounter with slightly inaccurate mocks in automated testing.
The better solution in my experience is to create an entirely different account to your production environments and just deploy things there to test. At least that way you're dealing with the real SQS, S3, etc, and if you have integration problems there, they're actually real things you need to fix for it to work in prod - not just weird bandaids to make it work with Localstack too.
The better solution in my experience is to create an entirely different account to your production environments and just deploy things there to test. At least that way you're dealing with the real SQS, S3, etc, and if you have integration problems there, they're actually real things you need to fix for it to work in prod - not just weird bandaids to make it work with Localstack too.