Kanban boards where dragging a card feels instant and a page refresh loses nothing.
↳ Drag-and-drop Kanban · Refresh-safe Boards
Concept brief: a Kanban workspace where dragging cards feels instant and boards survive a refresh.
Zustand state machine (isolated renders) + optimistic UI + Supabase Auth and Postgres persistence, with a one-click demo login so visitors skip signup.
Engineering outcomes (lab)
Board Persistence
Lost on refresh
Before
Zustand persist
After
Sign-in Friction
Sign-up wall
Before
One-click demo
After
State Updates
Full-board re-render
Before
Isolated store slices
After
Lighthouse mobile · connection range (2026-10-15)
150ms RTT: 99 · LCP 2.0s
Lighthouse preset
measured 16ms: 100 · LCP 0.7s
Measured line: the same build, not an improvement
Measured with Lighthouse 13 on mobile emulation, simulate throttling, median of 3 runs, against the live site on 2026-10-15. Published under two named profiles: Lighthouse’s mobile preset (150 ms RTT / 1.6 Mbps / 4× CPU), which anyone can reproduce, and this machine’s actual connection (16 ms / 4 Mbps / 4×), characterised by ping and a timed download rather than assumed. Connection assumption alone moves LCP by up to 3× on identical bytes, so neither figure is the whole truth alone. Lab numbers on a throttled connection, not client analytics or revenue data. No client affiliation implied.
Other builds
View all
Workouts, meals and progress in one place. Free forever, and the data never leaves your account.
Concept build: no real user data; not a medical, nutrition or fitness service.
Dark-mode portfolio tracking with charts you can read at a glance.
Concept build: the figures shown are seeded demo data, not financial advice.
Next build
FinTech Dashboard