TwinMind: meeting notes you can keep asking questions about
TwinMind is an AI assistant that turns conversations into notes and helps retrieve information from them. It serves people with frequent meetings who need to confirm decisions and tasks later; the desktop app also inserts dictated text into the app they are using.
Break down the problem and try your own design and implementation first. Then explore the reasoning to check states, edge cases, trade-offs, and ways to test your approach. The guide offers a reasoning path, not a complete implementation.
How should out-of-order transcript updates and Finish behave?
Design state-handling rules for a teaching transcription model. Inputs are Update and Finish events. Update contains sessionId, segmentId, revision (an integer increasing from 1) and text. Higher revisions replace lower revisions of the same segment. Finish contains only sessionId and ends that session. This is a proposed teaching model, not TwinMind's implementation.
- Accept updates only for the current session while it has not ended. Duplicate and lower revisions leave state unchanged. Ignore every update arriving after Finish. Display segments in the order they were first accepted.
- Walk through session A, segment s: revision 2 “Friday,” revision 1 “Thursday,” revision 2 again, Finish(A), then revision 3 “next Friday.” State the final text and why each ignored event was rejected.
- Deliver a state design, event-handling approach and test table covering an empty session, events from another session, repeated Finish and interleaved segments. Do not implement speech recognition.
Explore the reasoning
- Store session completion separately from each segment's latest revision. Segment identities are scoped to a session; do not reuse comparisons across sessions.
- Check session identity and completion before comparing revisions. After accepting revision 2, revision 1 leaves “Friday” unchanged; another revision 2 also leaves the order unchanged.
- Finish is this exercise's explicit cutoff, not a universal transcription rule. The final revision 3 is ignored too, so the final segment remains “Friday.”
- Use the table to establish idempotence (repeating an event has no further effect), stable order and rejection after completion. Discuss how the protocol would change to allow later corrections without silently changing the stated rules.
Where should a late answer go after switching notes?
Design a note question panel: users select a note on the left and enter a question and read the answer on the right. Requests contain noteId and requestId. A user may ask about A, immediately switch to B and receive A's answer later.
- Show only the latest request's result for the current note in the current panel. Older work may finish but must not overwrite newer content. Show the current note's name clearly after switching.
- Walk through A sends q1 → switch to B and send q2 → q2 succeeds → q1 succeeds. Also consider two questions on the same note and retry after failure.
- Deliver component state, conditions for accepting results and a keyboard interaction description. Keyboard users must be able to select notes, submit questions and perceive loading and errors. A complete UI implementation is not required.
Explore the reasoning
- Separate current noteId, current request identity and individual request states. The note name alone cannot distinguish two questions about the same note.
- In the example, B's q2 is displayed successfully; A's later q1 must not change B. Cancellation may save work, but correctness also needs a result-ownership check.
- Give a retry a new request identity and retain a readable error message. A late failure must not clear a newer successful result.
- Walk through an entirely keyboard-driven path with visible focus, continued access after submission and loading/error text perceivable by assistive technology. Control response order manually to verify interleavings instead of testing only fast successful responses.