In the evolution of application architecture from the 1990s to today, the traditional three-tier model—comprising data source, domain, and presentation tiers—has undergone significant transformations, primarily driven by the shift to web interfaces and the complexity of distributed systems. While the presentation tier evolved into the frontend and the domain tier into the backend, the increasing demands of computational and organizational complexity led to the development of microservices and serverless functions. This complexity introduced challenges in coordinating operations across distributed systems, necessitating the introduction of an orchestration tier to manage tasks across microservices. There have been two main approaches to orchestration: Do-It-Yourself solutions, which are complex and require deep system knowledge, and dedicated external orchestrators, which simplify usage but add architectural complexity. To address these challenges, the DBOS project proposes integrating orchestration functionality directly into the application tier through a lightweight library connected to a database, allowing for efficient management of distributed systems while maintaining the core advantages of modular application design.