Why this matters beyond the homelab: ADRs are standard practice on cloud and platform engineering teams. Practicing the discipline of documenting context, decision, and consequences maps directly to how infrastructure teams operate at scale.
The Problem ADRs Solve
Every infrastructure decision has two lifespans. The first is the moment you make it, when the context is vivid and the tradeoffs are obvious. The second is six months later, when you are staring at a config and asking why past-you did something that looks wrong.
Without a record, you get one of two bad outcomes. Either you re-litigate the decision from scratch and waste an evening rediscovering the constraint that forced it, or you “fix” it and rediscover the constraint the hard way, in production.
An Architecture Decision Record is a short document that captures three things: the context at the time, the decision made, and the consequences accepted. That is the entire format. The Alliance Fleet Codex now holds ten of them on a dedicated BookStack shelf.
What a Homelab ADR Actually Looks Like
Two examples from the fleet show the range.
ADR-008: VM placement policy. Which workloads belong on which Proxmox node, and why. Node-B carries the data and identity tier because it has ECC memory and ZFS. When I later found two VMs living on the wrong node, the ADR turned a judgment call into a compliance check: the document said where they belonged, so the July migration of Home-One and Coruscant to Node-B was not a debate, it was a work item.
ADR-010: Local model selection for agent workloads. The original decision selected qwen3:32b as the default model for Jocasta, the fleet’s AI agent. Reality intervened: 32b exceeded the 20GB VRAM on the RTX 4000 SFF Ada. Instead of silently swapping models, I wrote an addendum documenting the substitution to qwen3:14b, the measurement that forced it, and what capability was traded away.
That addendum is the part worth internalizing. ADRs are not carved in stone. When a decision gets revised, the record grows instead of being rewritten, and the reasoning chain stays intact.
The Discipline, Not the Template
The template is trivial. Context, decision, consequences, status. What matters is the habit:
- Write it when the decision is made, not after. Reconstructed context is fiction with good intentions.
- Record the rejected options. “We chose X” is half a record. “We chose X over Y because Z” is the part future-you needs.
- Amend, never erase. ADR-010’s addendum is more valuable than a clean rewrite would be, because it shows the decision surviving contact with hardware limits.
- Keep them findable. Mine live on Shelf 15 of the Codex, numbered sequentially, and they sync nightly into Git alongside the rest of the fleet documentation.
Key Takeaways
- Ten ADRs took maybe three hours of total writing time. They have already prevented one config regression and turned one migration from a debate into a checklist.
- The format is not the point. The point is that decisions become auditable artifacts instead of memories.
- If you are building a portfolio for infrastructure roles, ADRs are disproportionately valuable. They demonstrate the thing interviews try hardest to probe: how you reason about tradeoffs.