Keep the structure understandable
Use names that reflect the business and keep related behavior together. The next developer should be able to trace a user action through the code without exploring unrelated parts of the system.
Separate the parts that change differently
Content, visual presentation, and external integrations often evolve at different speeds. Clear boundaries help a design update avoid becoming a database rewrite, or a provider change avoid touching every screen.
Document the decisions that matter
Explain why an unusual choice was made, what assumptions it relies on, and when it should be revisited. A short decision note is often more useful than a diagram that no longer matches the application.
Improve through real feedback
Avoid building infrastructure for every hypothetical requirement. Start with a sound implementation, observe how it is used, and let evidence guide the next investment. Maintainability comes from clarity as much as flexibility.