Test assignments
Tumli Tasks
Time-slot task planner with drag-and-drop and optimistic updates with rollback.
- Role
- Front-End Developer
- Year
- 2026
- Type
- Test assignments
Overview
A day planner with 15/30/60-minute slots. The backend is mocked inside RTK Query with latency and random sync conflicts — to demonstrate that the UI stays responsive and rolls back correctly.
What I built
- Switchable 15/30/60-minute grid
- Task CRUD with inline rename on double-click
- Drag tasks between slots (@dnd-kit)
- Live labels: starts in / active for / completed at / overdue
Engineering highlights
- Real optimistic UI: onQueryStarted + updateQueryData + patch.undo() on failure
- Simulated 409 conflicts prove the rollback path; Panda CSS recipes for zero-runtime styles
