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Case · Financial tools · 2026

A legacy app rewritten in days

instead of months
Days
external PDF service
−€50/mo
per-seat fees
0
The project in facts
FormatA legacy app rewrite
Beforea low-code platform
Aftera modern stack
Pacea few days
The task

A financial calculator on low-code hit its ceiling.

The low-code app had done its job for years: calculations, conditional logic, PDF documents. But it ran slowly, every new feature was painful, and PDFs were generated through a separate paid service — about €50 a month.

We rewrote it from scratch on a modern stack in a few days with agentic development: a faster interface, PDFs generated in-app, Google and Facebook sign-in — and features the old platform simply didn't allow.

Context

What was in the way

  • Every new feature was painful
  • PDFs were generated through a separate paid service — about €50 a month
  • The platform priced per user
  • The interface was slow
Capabilities

What the system does

01

PDFs in-app

Documents are generated inside the app — no external services, no separate bill.

02

Sign-in

Login with Google and Facebook.

03

A faster interface

The app responds quickly — free of the old platform’s limits.

04

Features without a ceiling

Logic the low-code platform would not allow is now added natively.

What's inside

The engineering behind it.

Approach

Rewrite, don't patch

Instead of fighting the platform’s limits — a new app on a modern stack.

Pace

A few days

Agentic development: code is written and tested in parallel, so the rewrite took days, not months.

Quality

Fewer mistakes

The logic was rebuilt so users work faster and make fewer errors.

Results

Before → after

Before
After
A new feature meant pain and workarounds
Features are added natively
≈€50 a month for an external PDF service
PDFs generated in-app
Per-user pricing
No user limits
A slow interface
Fast on a modern stack

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