Why this matters
Polish depends on seams: data, permissions, state, failure, and the language between systems. Systems design makes those seams visible enough to preserve product intent.
Concepts to learn
- Canonical data ownership
- Bounded contexts
- State and failure models
- Permissions
- Performance and scaling
Apply It in Casset
Casset is the working environment for this skill—not the curriculum itself.
- Map the canonical owners across Profile World, Artist Runtime, Track Runtime, playback, permissions, and analytics.
- Identify one duplicated or transitional bridge and propose a migration that preserves behavior.
- Document what a new surface projects from existing owners rather than recreates.
Suggested project
Ownership map
A readable system map of the product nouns, owners, projections, and failure boundaries.
Evidence of completion
These are completion conditions, not claimed achievements. Each stays planned until it links to a real artifact or verification.
- diagramA canonical ownership diagramplanned
- pull requestOne duplication removed or boundary clarifiedplanned
- reflectionA tradeoff noteplanned
Open questions
- Which boundaries should remain stable while the product changes?
- How much architecture is enough to prevent drift without freezing the idea?
Related notes
Books, talks, and useful things
- bookDesigning Data-Intensive ApplicationsMartin Kleppmann
Reflection journal
The system is part of the concept's credibility, not the work that begins after the concept.