Serverless with an existing CloudFormation

I have an existing CloudFormation that is managed by a Python library (troposphere) and now I want to start using Serverless for managing my API Gateway and Lambda functions. Do you recommend converting the existing CloudFormation template to Serverless? Is it going to be painful to manage the stack using two different libraries?

Managing the stack with two tools would be fiddly, at best. Ideally you’d “slice” off functions/functionality and migrate them to Serverless piece-by-piece (but only ever having one tool to manage one component).

The answer to these questions will always be “it depends”. There are times when the best approach is to take a hit and spend the time converting the entire project at once. If your project is small, can’t be broken up or isn’t very complex then this might be the best approach for you. But if you’ve got a large project with a complex configuration then I would take @rowanu’s advice and try to slice of bits until you’ve been able to migrate the entire project.