system-architecture-harness

Think Through Production Systems

Overview

Turn an idea, requirement set, existing codebase, incident pattern, or migration goal into an evidence-backed architecture that can be built, operated, reviewed, and evolved.

Core principle: Architecture is a chain of explicit decisions under constraints—not a diagram, a technology list, or a collection of fashionable patterns.

Non-Negotiable Architecture Law

NO ARCHITECTURE DECISION WITHOUT:
1. a requirement, invariant, risk, or constraint that motivates it;
2. at least one realistic alternative;
3. a stated trade-off and consequence;
4. a way to validate the decision in production or before launch.

A component without a responsibility is decoration. A database without access patterns and consistency semantics is guesswork. A queue without delivery, ordering, retry, and replay semantics is an outage waiting for a date.

A user-requested scope limit never waives an applicable correctness boundary. In particular, an offline mutation or collaboration design cannot be made backend-only: the client is a stateful system component whose authority, durable state, lifecycle, failure behavior, and recovery must be designed.

When to Use

Use this skill for:

• greenfield system design;
• architecture review or due diligence;
• monolith/modular-monolith/microservice boundary decisions;
• scaling, performance, reliability, or cost redesign;
• data-platform, event-driven, real-time, financial, geospatial, storage, or AI systems;
• cloud, on-premises, hybrid, multi-region, edge, or offline-first deployments;
• migrations, decompositions, re-platforming, and legacy modernization;
• production readiness, threat modeling, disaster recovery, and operational design;
• architecture specifications, RFCs, ADRs, contextual AI reviews, and change handoff.

Do not use it as a substitute for product discovery, legal advice, formal safety certification, penetration testing, or domain-expert approval. It should expose when those are required.