Sparround

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.

StepWhat to doWhy it matters
1. ClarifyWhere the data comes from, how large the list is, whether offline is neededA solution built on a wrong assumption cannot be salvaged
2. State the structureDescribe the widget tree aloud, then write itIt lets the interviewer redirect you early
3. Write and narrateVoice each decision: "Expanded here, because..."Silence is the worst signal — your thinking is invisible
4. Cover the statesLoading, empty, error — name them even if you do not write themIt is the most visible junior-to-middle difference
5. Wrap upSay what you simplified and what you would do nextEven 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