freeCodeCamp’s roughly three-hour system design course applies a five-step approach to services resembling Spotify, Booking.com, and WhatsApp. Its official introduction describes clarifying ambiguous requirements through questions, starting with a simple architecture, estimating traffic and storage, and discussing bottlenecks and technological trade-offs. The material connects choices such as WebSocket versus HTTP and load balancers with interview evaluation criteria. This review covered the public introduction and official course description, not every detail of the video or the actual internal architectures of those services.