Explore the challenges and advancements in modern application delivery through a comprehensive retrospection of KubeVela's highlight technologies. Delve into the evolution of KubeVela since the inception of the Open Application Model in 2019, covering its journey to becoming a CNCF incubating project. Learn how KubeVela balances extension capabilities with user experience, provides powerful orchestration features, manages resources effectively, and ensures stability at scale. Gain insights into the project's approach to abstraction, compatibility, data passing, multi-environment delivery, rollout strategies, and resource sharing. Discover solutions for horizontal scaling, performance optimization, and bottleneck identification in large-scale deployments. Benefit from the maintainers' experience with diverse user scenarios, including those from Alibaba Cloud and China Merchants Bank, as they share key learnings from three years of project development.