I never had a case where cold starts mattered because either 1) it was the kind of service where cold starts intrinsically didnt matter, or 2) we generally had > 1 req/15mins meaning we always had something warm.

3) Also you can pay for provisioned capacity[1] if the cold start thing makes it worth the money, though also just look into fargate[2] if that's the case.

[1]: https://docs.aws.amazon.com/lambda/latest/dg/configuration-c...

[2]: https://aws.amazon.com/fargate/