Checklist for documenting a medium to large scale system architecture

Posted on 03 Feb, 2024
Some items that can help you document a undocumented legacy system.
  • Identify common points of failure in the architecture.
  • Identify uptime maintained in the last year (in 9s).
  • Identify maintainer/dev team size.
  • Identify specific version numbers of SDKs, APIs and packages used.
    • Identify if updating SDKs can break the system.
  • Get entire server inventory list with os details.
  • Create documentation for the deployment strategies.
  • Create as many flowcharts/visual representations of the modules as possible. Way more than textual documents.
  • Make notes. Make lots of notes. Don't discard/delete anything. When you are actually documenting things, make sure all the notes you have made are checked for inclusion.


  • Big thanks to folks on developersIndia and The Engineerin Org discord for their inputs.