Local development tooling
Similar to AWS SAM (https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-using-invoke.html) or Google Cloud Functions Framework (https://cloud.google.com/functions/docs/functions-framework).
I.e. the ability to run functions locally. It's expensive and slow to have to run and test code in a project remotely all the time even for small changes.
Not only for functions, but also please consider local tooling for graphql.
AWS Amplify has a local development feature which is really useful. Just run a simple command `amplify mock api` then you get a locally running graphql endpoint. It really speeds up both development and testing.