Real-time financial dashboard for a Series A fintech. Rebuilt from scratch in 6 weeks — 240% engagement lift on launch day.
* Client name and identifying details changed to protect confidentiality.
Meridian came to us six months post-Series A with a product that worked but didn't feel like it was worth $12M in funding. Their dashboard was a patchwork of third-party widgets, a legacy chart library from 2019, and a navigation structure that made power users file support tickets. Churn was climbing. The board had questions.
Their CTO had a clear directive: ship a completely rebuilt frontend in under two months without touching the backend API. The data layer was solid. The presentation layer was not.
"Our users kept telling us the product felt 'clunky.' We knew what we had to do — we just couldn't afford a 6-month redesign cycle."
— VP Product, Meridian FinanceThe original dashboard polled the API every 30 seconds and re-rendered the entire component tree. We replaced it with a WebSocket-driven state layer using Zustand, with selective re-renders keyed to data stream IDs. P99 response time dropped from 1.4s to under 180ms for live portfolio updates.
We ran 12 sessions with power users before writing a line of code. The core insight: 80% of daily workflows centered on three actions — checking positions, reviewing recent transactions, and running quick comparisons. Everything else was noise. We restructured the nav around those three core jobs and pushed the rest into secondary drawers.
We ditched the legacy library and built a custom charting layer on top of D3 and React, giving Meridian's design team full control over theming and interactive states. Candlestick, sparkline, area fill, and comparison overlays — all built in-house, all accessible, all performant at 60fps on 5-year-old hardware.
Every component shipped with Storybook documentation and TypeScript prop types. Meridian's in-house dev team could extend the library without waiting for an agency ticket. That was a hard requirement from day one — they weren't buying a black box.
We shipped to production on day 41. The remaining three days of the six-week engagement were spent on QA and documentation handoff.
"NextDay delivered something our team genuinely couldn't have built in that timeframe. The component library alone saved us months of future work."
— CTO, Meridian Finance