So I've never actually done this, but I think this makes sense: You can just structure your code in this way -- divide hard boundaries in your monolith. Segmen

So I've never actually done this, but I think this makes sense: You can just structure your code in this way -- divide hard boundaries in your monolith. Segment things apart the same as they would be in microservices. Have a collection of methods for accessing each segment of code, and don't allow calling anything but that collection (API) from other parts of the codebase. Set up monitoring/logging. If a segment of your code is using a huge amount of resources, it'll now be trivial to pull that segment out into its own microservice because you already have a defined API and hard boundaries.