📄 Design Documentation & Architecture

Capture problem context, goals, and solutions in comprehensive design docs to enable alignment and reduce rework.

Before writing code, I write down what I’m building and why. A design doc forces me to articulate the problem context, articulate the goals and non‑goals, and think through the architecture before diving into implementation. For any feature that will take more than a few weeks, I start with a short document that outlines the high‑level overview, the problem statement, and the success criteria. This exercise often surfaces hidden assumptions and sparks discussions that save time later.

Comprehensive design docs include more than just a diagram. I list the authors, stakeholders, and timelines up front, then describe the existing solutions and constraints. The proposed solution section is broken into a high‑level architecture (supported by diagrams) and detailed component descriptions. I include alternative approaches and the trade‑offs considered, along with a testability and monitoring plan. A section on cross‑team impact and open questions ensures that adjacent teams aren’t surprised by future dependencies.

Design docs are living documents; they evolve as projects progress and decisions are made. I store them in version control alongside the code so revisions can be reviewed and discussed. Decision logs capture the reasons behind changes, helping future engineers understand why things were done. Keeping design docs up to date reduces the “bus factor,” improves onboarding, and makes it easier to reason about the system as it grows.

Above all, design documentation is about alignment. It gives everyone a shared understanding of the problem and solution and provides a forum for feedback before the cost of change rises. The goal isn’t to predict every detail, but to reduce ambiguity and prevent costly rework down the line.