Sohnics.
Sohnics.
Case study · Web Platform · Fintech

Northwind Capital
2025

Rebuilding a 12-year-old fintech without losing a single user.

Client
Northwind Capital
Category
Web Platform · Fintech
Duration
14 weeks
Year
2025
Northwind Capital
Overview

Northwind's investor portal had grown organically since 2013 — three frameworks, two databases, and a checkout that timed out at peak hours. We rebuilt it from the database up.

The challenge

What we walked into.

Eight-second TTFB on the dashboard. A 41% drop-off at KYC. Quarterly outages every earnings week. And a board that wanted more features, not a rebuild.

Approach

How we engineered it.

  1. 01

    Mapped the legacy system end-to-end and identified the four hot paths owning 80% of revenue.

  2. 02

    Stood up a new TanStack Start + PostgreSQL stack on Cloudflare edge, behind a feature-flagged proxy.

  3. 03

    Migrated one bounded context per sprint with shadow traffic comparisons before cut-over.

  4. 04

    Rewrote the KYC flow with progressive disclosure and inline validation — cutting fields by 38%.

Outcome
0%
Faster TTFB
0%
Conversion lift
0%
KYC drop-off cut

Shipped in 14 weeks with zero downtime. TTFB dropped from 8s to 0.4s. KYC drop-off fell from 41% to 12%. Conversion rose 184% in the first quarter.

Stack
TanStack StartTypeScriptPostgreSQLDrizzleCloudflare WorkersPlaywright

"We expected a redesign. We got a different company. The platform feels twice as fast and the team finally trusts release day."

Maren Holt · VP Product, Northwind Capital

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