Live coding and architecture discussion
The practical part of a Flutter interview is usually one of two formats:
- "Build this screen" — writing a widget tree from a design or description
- "How would you architect this app?" — an architecture discussion with no code
In both, what is assessed is not a finished answer but the process: do you ask questions, state assumptions out loud, recognise trade-offs.
The step most often skipped is the first one: most candidates start typing immediately. Yet a 30-second clarifying question — "is the list infinitely scrolling or bounded?", "is offline support required?" — changes the direction of the entire solution.
| Step | What to do | Why it matters |
|---|---|---|
| 1. Clarify | Where the data comes from, how large the list is, whether offline is needed | A solution built on a wrong assumption cannot be salvaged |
| 2. State the structure | Describe the widget tree aloud, then write it | It lets the interviewer redirect you early |
| 3. Write and narrate | Voice each decision: "Expanded here, because..." | Silence is the worst signal — your thinking is invisible |
| 4. Cover the states | Loading, empty, error — name them even if you do not write them | It is the most visible junior-to-middle difference |
| 5. Wrap up | Say what you simplified and what you would do next | Even out of time, it shows you saw the whole picture |
Interview tip. In an architecture question ("how would you build something like Instagram?") the trap is trying to cover everything. The strong approach: ask about scale (a hundred users or a million?), then focus on one or two critical decisions and go deep — feed pagination and caching strategy, say. Skimming ten topics lands worse than treating two properly.
📚 Sources and documentation
- App architecture guideofficialdocs.flutter.dev
- Architecture case studyofficialdocs.flutter.dev
- Performance best practicesofficialdocs.flutter.dev