monthlymuster.vercel.app
ConceptWeb Application
14 daysMonthlyMuster
Kanban boards where dragging a card feels instant and a page refresh loses nothing.
Drag-and-drop KanbanRefresh-safe Boards
Case study & metrics
All work
FinTech DashboardConcept build
TellersWindow
Dark-mode portfolio tracking with charts you can read at a glance.
Concept build: the figures shown are seeded demo data, not financial advice.
↳ Live Data + Seeded Fallback · Mobile-first
- Next.js
- TypeScript
- Recharts
- CoinGecko API
- Shipped
- 21 days · FinTech Dashboard
- Stack
- Next.js · TypeScript · Recharts
- Outcome (lab)
- Live Data + Seeded Fallback · Mobile-first
tellerswindow.vercel.app
tellerswindow.vercel.app
01
The challenge
Concept brief: a fintech dashboard that stays usable on mobile: live prices, graceful fallback when the API fails, no blank screens.
02
The solution
Type-safe TypeScript architecture with a resilient data layer: live CoinGecko prices backed by a seeded fallback so the dashboard never renders empty. Memoized Recharts components and aggregated series keep mobile scrolling smooth.
03
Key outcomes (lab)
- Mobile-first responsive layout
- Type-safe end-to-end architecture
- Graceful API-failure fallback
Engineering outcomes (lab)
Measured on the concept build.
Market Data
Static mock
Before
Live CoinGecko feed
After
API Failure UX
Blank dashboard
Before
Seeded fallback
After
Type Safety
Unchecked
Before
Strict, zero errors
After
Lighthouse mobile · connection range (2026-10-15)
150ms RTT: 99 · LCP 2.0s
Lighthouse preset
measured 16ms: 100 · LCP 0.8s
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.
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Web Application