System Design Interview Questions

The classic warm-up question. Shows whether a junior can decompose a simple system into components and think about data flow, even if they haven't built distributed systems yet.

Filters out candidates who pick databases based on hype instead of data characteristics. The blog context makes it concrete enough that vague answers stand out.

Load balancing is infrastructure 101. A junior who can explain basic distribution algorithms has some exposure to how deployed systems actually work.

Caching is the first performance tool every developer should reach for. The follow-up about invalidation reveals whether they've actually implemented caching or just read about it.

Developers who confuse async programming with async architecture will make poor integration decisions. This question surfaces that confusion early.

Data modeling is a skill that every developer needs regardless of their role. Storing a cart as a JSON blob is a common mistake that haunts teams for years.

Onboarding speed is a huge factor for remote and augmented teams. A structured learner becomes productive in days, not months.