Microservice Architecture - What Are the Technology Changes?

Most people I've met with over the years have been developed already. And even newer companies like, you know, startups that are just a few years old,. They have started with a monolith which is usually a good approach by the way. But very rapidly, particularly VC funded startups, find that they actually got a big application, big monolith on their hands. And they need to split it up and migrate it to a microservice architecture.