At Swisscom, we are engaged in an ambitious technology and cultural transformation towards cloud-native readiness. The advent of new technologies and open source tools has provided us with the opportunity to rethink how we build and operate our 5G Core. By leveraging these technologies, we have taken the chance to ban the widely adopted use of spreadsheets and files "stored anywhere" and adopt a GitOps approach. This has enabled us to introduce DevOps best practices for application development, such as version control and CI/CD/CT for both infrastructure and applications. Our strategy of utilizing state-of-the-art tooling and a new willingness to embrace a "try fast and fail fast" mentality was crucial in finding the optimal solution to address various challenges. Early experience and lessons learned have guided us towards advanced templating practices, which go beyond simply copying and pasting environments. Low-level design as code and repository/branching strategies were instrumental in enabling us to automate at scale and streamline the instantiation, configuration, testing, and lifecycle management of 5G core services. In this presentation, we will showcase the evolution of the mobile network core in regards to deployment, configuration, and testing of 5G network functions on Kubernetes using Flux, Ansible, GitLab, Grafana & Kubernetes Operators.