Documentation & Requirements

Overview

Software specifications capture the "what" and "why" before implementation addresses the "how." Well-structured requirements documents, architecture decisions, and executable specs reduce ambiguity, align stakeholders, and create verifiable acceptance criteria.

Document Types

Requirements Documents

Type	Audience	Focus
PRD (Product Requirements)	Product + Engineering	Features, user stories, success metrics
TRD (Technical Requirements)	Engineering	Architecture, APIs, data models, constraints
BRD (Business Requirements)	Business + Leadership	ROI, market need, business objectives

Architecture Documents

Type	Audience	Focus
ADR (Architecture Decision Record)	Engineering	Single decision with context and consequences
RFC (Request for Comments)	Engineering + Stakeholders	Proposed change seeking feedback

Executable Specifications

Type	Audience	Focus
Gherkin (Given/When/Then)	QA + Product + Engineering	Acceptance criteria as executable tests
Gauge (Markdown specs)	QA + Engineering	Free-form test specifications in Markdown

Document Flow

Business Need
    │
    ▼
  BRD ──► "Should we build this?"
    │
    ▼
  PRD ──► "What are we building?"
    │
    ├──► ADR ──► "Why did we choose X over Y?"
    │
    ▼
  TRD ──► "How do we build it?"
    │
    ├──► RFC ──► "Proposing approach Z for feedback"
    │
    ▼
  Gherkin / Gauge ──► "How do we verify it works?"
    │
    ▼
  Implementation + Automated Tests

Best Practices

• Write the PRD before the TRD — define what you're building before deciding how to build it.
• Use ADRs for every significant architecture decision — they're short, structured, and invaluable for future developers.
• Make specifications executable where possible — Gherkin and Gauge connect written specs directly to automated tests.
• Keep documents close to the code in the same repository so they evolve together.
• Use lightweight templates rather than heavyweight processes — a short, focused ADR beats a 50-page design doc nobody reads.
• Review specs before implementation, not after — specifications are cheapest to change when they're still text.