Early architecture choices often look small until traffic, team size, or product complexity increases. The goal is reversible decisions and clear boundaries.

Start by identifying what must remain stable: domain language, ownership boundaries, and data contracts. Leave implementation details free to change as usage patterns emerge.

A useful heuristic: optimize for clarity of change. If a new requirement forces edits across many unrelated modules, the architecture is signaling a boundary problem.

Document the why behind major decisions. Future teams will inherit the constraints you create; they should also inherit the reasoning.