Architecture Decisions

Architecture Decision Records

Index of architectural decisions made in the HanseNexus monorepo

What are ADRs?

Architecture Decision Records (ADRs) are lightweight documents that capture important architectural decisions made in the project, along with their context and consequences. They help:

  • Document why decisions were made — not just what, but why
  • Provide context for future maintainers — understand the reasoning behind choices
  • Track architectural evolution — see how and why the architecture changed over time
  • Facilitate onboarding — new team members can quickly understand key decisions

We use the MADR (Markdown Architectural Decision Records) format, which is lightweight, readable, and version-controlled alongside the code.

Index of ADRs

NumberTitleStatusDate
0001Turborepo Monorepo StructureAccepted2025-02-03
0002Convex as Backend PlatformAccepted2025-02-03
0003Shared Package StrategyAccepted2025-02-03
0004Bun as Package ManagerAccepted2025-02-03
0005Tailwind CSS v4 AdoptionAccepted2025-02-03
0006Next.js 16 Proxy MigrationAccepted2025-03
00071Password Secret ManagementAccepted2025-03
0008Self-Hosted ConvexAccepted2025-03
0009OTel + SigNoz MonitoringAccepted2025-03

When to Write an ADR

Write an ADR when making decisions that:

  • Affect the project structure (monorepo layout, package organization)
  • Choose core technologies (frameworks, databases, build tools)
  • Define architectural patterns (state management, API design, auth flow)
  • Impact multiple teams or apps (shared packages, coding standards)
  • Are hard to reverse (database schema, core dependencies)
  • Need explanation (non-obvious choices, tradeoffs)

How to Create an ADR

  1. Copy the template: cp docs/adr/template.md docs/adr/XXXX-your-decision-title.md
  2. Number it sequentially using the next available number
  3. Fill in the sections: Status, Context, Decision, Consequences, Alternatives Considered
  4. Keep it concise — ADRs should be readable in 5-10 minutes
  5. Commit the ADR alongside the code it documents

Resources

HanseNexus 2026