System Design
How to design scalable, reliable backend systems: APIs, databases, caching, queues and trade-offs.
What you are tested on
- Requirements and estimation
- APIs and data models
- Caching and load balancing
- Queues and asynchronous work
- Consistency and failure
Practice problems
Roadmaps
System Design Roadmap
Reason about scale: the building blocks, the trade-offs, and how to walk through a design.
Product-Minded System Design and Observability Roadmap
Design systems that scale and can be understood in production, with a habit of tying choices to product needs.
Freelancing and Startup Founder Path for Engineers
Turn your skills into income or a company: find real problems, ship early and learn to sell.
How your System Design rating works
You start at 1200. Each timed, rated test moves your System Design rating up or down, the way chess ratings move. Recruiters see the number and the band (Beginner, Intermediate, Advanced or Expert), so they can judge your skill before reading a résumé. See a sample profile.
Questions about System Design
Do freshers get system design questions?
Usually a light version: design a small service, choose a database, explain trade-offs. Full-scale design is asked from experienced hires.
How do I practise?
Pick a familiar product (URL shortener, chat), list requirements, sketch components and defend your choices.