For rendering and API logic we opted entirely for lambdas. There is a fine line between where do you split routing between APIG and Lambda. In reality the lambdas contain a lot of the same imported code so perhaps we could argue it'd be better as a containerised system. We liked how you can very quickly update a single lambda from SLS, and the lambda deployment options are extensive. Our business logic is complex so removing having to deal with deployment and operations has been the biggest benefit timewise.