eco-design

eco-design

Walk through sustainability considerations for an architecture or feature being planned. Unlike eco-review (which audits existing code), eco-design is forward-looking — it checks whether the design being discussed has considered greener alternatives at each decision point.

Important: eco-design only evaluates the design document or plan being discussed. Do not scan or audit the existing codebase — that is eco-review's job. Only read existing code if you need to understand context for a decision the design document explicitly introduces (e.g., understanding an ORM pattern to inform a new entity's access strategy). Never surface findings about existing infrastructure, CI configuration, logging, or other concerns that are not part of the proposed design. If the design document does not mention a topic (e.g., CI/CD, container images, cloud regions), do not raise it.

Process

1. Read the design document — the design doc, plan, or conversation so far. Check for .eco-ignore in the project root; skip any decision points whose pattern ID is listed there.
2. Identify decision points — which items from the checklist below are relevant to decisions introduced or changed by this design
3. Present recommendations — for each relevant decision point, present the eco-first alternative with its rationale and citation
4. Discuss with developer — ask whether they want to adopt each recommendation; accept pushback on compliance, latency, or cost constraints
5. Summarize — list accepted, declined, and deferred recommendations

Decision Points Checklist

Infrastructure Decisions

Region selection If the design specifies a cloud region, look it up in data/carbon-intensity.md. If it's in the "High Carbon" tier, suggest a lower-carbon alternative in the same provider with comparable latency. Technical risk: Data residency/compliance violations, migration downtime, cross-region replication complexity. Usability risk: Higher latency for users near original region. Reference: I1 — Google Cloud Region Carbon Data, 2024