Migrating off Zoho Creator: how we rewrote a financial calculator

By: Andrew Maryasov · Jul 6, 2026 · 5 min read

Before and after migrating off Zoho Creator: a slow, aged financial calculator that was painful to extend, rewritten with Claude Code in a few days with calculations, tables and PDF generation — Why “a few days” is not marketing

What was there: why did it hurt?

The app had done its job for years — which is exactly why nobody touched it for so long. But it ran slowly, it had aged badly, and every new feature was added with pain: the platform simply was not built for that level of complexity. Any further development ran into a ceiling.

One detail that sums up the whole situation: PDF documents were generated through a separate paid service. In other words, around €50 a month went to something that should have been a basic function of the app itself.

What did we do?

We took Claude Code and rewrote everything from scratch on a modern stack in a few days. The interface got faster. PDFs are now generated inside the app — no external services and no separate bill for them.

Then we started adding things nobody had even attempted on Zoho Creator, because the platform would not allow them. We rebuilt the workflow logic; we did not measure working speed or error counts, and the client noted the change subjectively. We added sign-in via Google, Facebook, email and SMS — everyone logs in the way they are used to.

What did the client get?

A faster interface instead of an app that had aged badly.
PDFs inside the app — minus around €50 a month spent on a third-party service.
Features that were out of reach on the old platform, and logic that cuts down mistakes in daily work.
No per-user pricing: most low-code platforms charge for every seat, and the bill grows with the team. Not here.

The bottom line: free scaling and an app that can grow without a ceiling, instead of a platform that hit one with every new feature.

Why isn't “a few days” marketing?

The skepticism is fair: “rewritten in a few days” sounds like an ad slogan. But this is not speed for its own sake, and not because we are geniuses — the tools have fundamentally changed. Two years ago a custom business app meant either committing to an expensive platform or hiring a development team for months. Small businesses simply could not afford it. Now the barrier to entry has dropped so far that things that used to take a team months of work get done in days.

And it is not slowing down — the opposite: every month something appears that shifts the bar again. It feels like standing on a platform, watching a train that has already picked up speed. You can still jump on. You can stand and watch it go. But it is definitely not going to stop.

What if you also have an app that hurts?

A CRM, a calculator, an internal portal — it does not matter what exactly. If it runs on an old platform but every change comes with pain, that is no longer a life sentence or something to put up with. Write to us — we will look at what can be rebuilt on a modern stack.

Rewriting legacy apps is our own work at Auspex — it is our application-development service, and Claude Code is a developer's tool here. If the process itself needs an AI agent — handling inquiries, qualification, front-office — that is built by Grow2.ai, our AI division. They are different jobs and worth keeping apart.

The tools have changed. What required a development team and months of work two years ago now gets done in a few days. An app on an old platform that works but hurts is no longer something you just have to live with.

Frequently asked

We also have an old app, but not on Zoho Creator. Can it be rewritten?

Yes. Zoho Creator in this case is a specific example, not the limit of the approach. The pain is usually the same: the platform has run its course, the interface is slow, some features are impossible, and paid third-party services sit alongside, patching the holes. If your app works but already hurts — write to us, and we will look at what can be rebuilt.

Why not keep building on the platform itself?

You can — as long as the platform allows it. In this case that was exactly the problem: every new feature came with pain, some things were never even attempted on Zoho Creator, and PDFs had to be moved out to a separate paid service. Once development hits the platform's ceiling, every improvement becomes a fight against constraints rather than product work.

How long does a rewrite like this take?

This calculator — calculations, tables, conditional logic, PDFs — was rewritten in a few days. That is not a universal promise: the timeline depends on the complexity of the specific app. But the order of magnitude has changed — with tools like Claude Code the conversation is about days, not the months this kind of work used to take.

How much does it cost?

There is no fixed price here — it all depends on the complexity of the app. First we look at what you have and give an estimate for the specific scope. A reference point from this case: the client immediately shed around €50 a month in third-party PDF service costs and no longer pays per user.

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