This software conforms to 12-factor methodology. The 12-Factor methodology is a set of best practices for building modern, scalable, maintainable software-as-a-service apps. These principles were first presented by engineers at Heroku, a cloud platform as a service (PaaS) company. Following are the salient points of how this project adopts these best practices.

  1. Codebase: [✅] One codebase tracked in revision control, many deploys
  2. Dependencies: [✅] Explicitly declare and isolate dependencies. We’re using Terraform’s built-in package lock, Python’s requirements files, and NPM’s package.json to declare dependencies.
  3. Config: [✅] Store config in the environment. This project implements a special Settings class, which both validates and stores all configuration information for the package.
  4. Backing services: [✅] Treat backing services as attached resources. We’re using LangChain in this project to further abstract the code from the technical specifics of whichever LLM we use for prompting.
  5. Build, release, run: [✅] Strictly separate build and run stages. Build is implemented in Makefile, release is implemented as a GitHub Action, and run is independently managed by AWS API Gateway.
  6. Processes: [✅] Execute the app as one or more stateless processes. This REST API as well as the Lambda functions it calls are stateless.
  7. Port binding: [✅] Export services via port binding. This micro service listens on ports 80 and 443.
  8. Concurrency: [✅] Scale out via the process model. We achieve this “for free” since we’re using AWS serverless infrastructure, which is inherently and infinitely scalable.
  9. Disposability: [✅] Maximize robustness with fast startup and graceful shutdown. Terraform takes care of this for us. Running terraform destroy will completely remove this project and any residual data from your AWS account.
  10. Dev/prod parity: [✅] Keep development, staging, and production as similar as possible. The GitHub Action pushMain.yml executes a forced merge from main to dev branches. This ensure that all dev branches are synced to main immediately after pull requests are merged to main.
  11. Logs: [✅] Treat logs as event streams. We get this “for free” by using AWS Cloudwatch.
  12. Admin processes: [✅] Run admin/management tasks as one-off processes. All admin processes are implemented with GitHub Actions and other GitHub management features. The Terraform command lines services as our admin console for this API.