As Uber is hyper-growing as a company so does our need for scalable and resilient systems. In this talk, I’m going to tell the story of how my team migrated from Python to Go, a microservice that processes millions of events every day. First, we are going to start with the rationale behind the migration. Then we are going to go over the Python and Go tech stacks that we use. Last but not least, I’m also going to share our approach for migrating the service while running in production, adding new features and making sure there are no regressions.