How do you design systems that are scalable and maintainable?

Short answer: I start by understanding the business growth projections and expected user load.

Explain a bit more

Architecturally, I favor modularity—breaking the system into well-defined services or components. For example, using microservices in .NET Core allows independent scaling. On the frontend, reusable React components improve maintainability. I also enforce clear API contracts and automate testing to ensure future changes don’t break things. Documentation and knowledge sharing are key so the system is maintainable even as teams grow or shift.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.