Welcome to Continuous Improvement, the podcast where we explore cutting-edge methodologies and best practices that enhance how we build software. I’m your host, Victor Leung, and in today’s episode, we’re unpacking a crucial methodology for anyone working in the realm of Software-as-a-Service or SaaS—The 12 Factor App. Developed by the engineers at Heroku, this set of guidelines has transformed how applications are built and deployed on modern cloud platforms.

To start, let’s talk about why the 12 Factor App methodology was created. In the early days, web applications were often built as monoliths—large, single units that were tightly coupled with their environments. This created a myriad of problems, especially when these applications needed to scale or be moved to different environments.

The 12 Factor App methodology was designed to overcome these challenges. It emphasizes a declarative format for automation setup, a clean contract with the operating system, and a drive to minimize the gap between development and production. These practices ensure that applications are portable, scalable, and maintainable. Let’s break down these factors.

Factor 1: Codebase. There should be exactly one codebase for a service, with the codebase being used for many deployments. This means having a single repository that can be deployed anywhere, from the developer’s local environment to the final production servers.

Factor 2: Dependencies. Your application should explicitly declare and isolate dependencies. This avoids the pitfalls of implicit dependencies that can lead to conflicts between differing environments.

Factor 3: Config. Configuration settings should be stored in the environment rather than in the code. This separation of config from code helps keep the application environment agnostic, making it easy to adjust settings without changing the codebase.

Factor 4: Backing Services. Treat all backing services as attached resources which can be attached or detached to deployments without significant changes to the code.

Factor 5: Build, Release, Run. Strictly separate the build and run stages. By doing this, applications are more stable and predictable since no changes are allowed that might affect the running application during the release phase.

Factor 6: Processes. Execute the app as one or more stateless processes. This is crucial for scalability and distribution since no user session or context is stored locally.

Factor 7: Port Binding. The application should be self-contained and not rely on runtime injection of a web server.

Factor 8: Concurrency. Scale out via the process model. Essentially, this involves starting more copies of the application to handle more load.

Factor 9: Disposability. Maximize robustness with fast startup and graceful shutdown. This improves the application’s reliability in the face of hardware/software failures.

Factor 10: Dev/Prod Parity. Keep development, staging, and production as similar as possible to avoid bugs that arise from environmental differences.

Factor 11: Logs. Treat logs as event streams. This allows for more scalable and manageable logging.

Factor 12: Admin Processes. Run administrative/management tasks as one-off processes. This ensures that these tasks are performed without affecting the running application’s environment.

The 12 Factor App is more than just a methodology; it’s a philosophy for software development and deployment. It’s about building software that is robust, manageable, and above all, adaptable to the changes and scales as needed without a complete overhaul.

Thanks for joining me on Continuous Improvement. Whether you’re building your next big SaaS or scaling an existing one, keeping these 12 factors in mind can be the difference between success and failure. I’m Victor Leung, and I’ll be back soon with more insights and strategies to help you refine your craft and improve your projects. Until next time, keep coding, keep improving, and stay cloud-savvy.