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Interview prep · Lesson 49 of 98 · 54 min video, then about 3 hours of practice
Light system design for junior interviews
After this you can sketch a simple web system with clients, servers, a database and a cache, and talk through basic trade-offs.
Why it matters
Junior roles increasingly include a light design question: how would you build a URL shortener or a to-do app for many users. Nobody expects distributed-systems depth. They want to see you ask about requirements, draw the obvious boxes, and reason about where it would get slow. The System design phase later in this roadmap goes much deeper; this is the interview subset. Trap: jumping straight to microservices and Kafka. Start simple and scale only when the requirements demand it.
How to use this resource
Core concepts at the right level for a junior interview.