Introduction · Designing the client
What is frontend system design-style app
Illustrative system design for a designing the client app like What is frontend system design: 3 topics to read, from requirements to deep dives.
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Start with The client Sign in to start readingUpdated 2 Oct 2026
Core
In a frontend design the server is a black box with a contract; what you design is everything between that contract and the pixels: views, a client store, a data-access layer, and the rules for when each one changes.
A frontend design prompt is either a whole application (many screens, a server, navigation) or one reusable component (one widget, deep on keyboard, focus and API); spotting which decides where the time goes.
Reviewers look for a handful of signals: you scoped before you built, split the client into parts with clear owners, knew the browser, weighed options, cared about the person using it, and talked through it; each has a recognisable failure.