This article discusses the development workflow of a 100% serverless company, Lumigo. The guiding principles and tools used at Lumigo aim to ensure an efficient workflow. Serverless development requires a different approach, focusing on adopting a mindset that prioritizes efficiency and embracing managed services. Key aspects of the workflow include detecting problems early, automating testing and linting, and using cloud-based toolchains. The article also highlights the importance of developers being responsible for monitoring and maintaining their code. The technical stack used at Lumigo includes Python 3.7, NodeJS 8.10, Jira, GitHub, Pytest, Flake8, Serverless, CircleCI, CodeCov, and lumigo.io. The workflow is designed to be flexible and adaptable, with a focus on continuous integration and delivery.