SERVICE / LEGACY REPLACEMENT

No specification left? We can still rebuild it.

The people who built it have gone, and no specification survives. Even then, we read how it runs today, turn that into a specification, and rebuild it with tests. We built a copy of a core system that had run for over 20 years in 2 weeks.

See how it works

We reply to enquiries and quote requests within 24–72 hours. Even before your requirements are settled, we work alongside you, turning the conversation into a specification.

When this helps

Does any of this sound familiar?

No specification is leftThe running code is the only specification. Nobody in-house can touch it, so you cannot even get an estimate for a change.

It cannot be stopped, and it cannot hold much longerIt sits in the middle of the business, so it cannot be stopped. Meanwhile the server and the language are old, and keeping it running is the riskier path.

SaaS fees have grown out of handYou need a few of the features, yet you keep paying licences for the whole company.

What we provide

What we do.

We read the screens and the processing of your current system, and only what you approve goes into the specification
We deliver one working feature at a time. There is no single hand-over once everything is finished
Every feature passes tests and security verification, so you can confirm nothing broke in the move
Data migration is part of the design. We replace the system without stopping how you work today

Track record

This speed is already happening on real projects.

All of these are real projects built with Hora Kit. Conventionally they would run to months of work.

2 weeksA copy of a legacy system builtA core system that had run for over 20 years

10 million+ recordsSalesforce replaced from scratch for a staffing companyIncluding over 100 automation flows and advanced search. Annual licence costs cut substantially

Under JPY 10,000,000The Tamago Cart e-commerce cart replacedAll customer data migrated. Replaced without stopping the running store

How it works

Four steps, each one confirmed before the next.

Only what you approve becomes the specification, and you check it on working screens before it goes to production.

STEP 01ConsultationNo need to have your requirements ready. We sort them out together, in conversation.STEP 02Agreeing the specificationOnly what you approve goes into the specification.STEP 03Development and testingEach feature is built and passes automated tests and security checks.STEP 04Acceptance and releaseYou check it on working screens before it goes to production.

Why it is fast

Speed and quality are not a trade-off.

The speed comes from Hora Kit, the AI development framework we build ourselves and publish as open source.

Five years of know-how, in more than 200 promptsEverything we have learned since founding is organised task by task and fixed as a workflow. Quality no longer depends on who happens to do the work.Tests and E2E tests for every featureEvery feature has test cases, and E2E tests reproduce real screen operations automatically. Each time a feature is added, the existing ones are checked automatically for breakage.Security verified automatically before releaseInput handling, authentication and information leakage are verified automatically, feature by feature. Vulnerabilities are closed before anything reaches production.

The same quality, at an order of magnitude less.

PLANRapid developmentConventional development costseveral million to several tens of millions of yen

With Hora KitFrom several hundred thousand yen, up to JPY 5,000,000

* The amount varies with the timeline, the scope and the state of the existing system. We start by giving you a rough estimate.

Start by seeing that speed and quality for yourself.

Show us a few screens of your current system, and we will come back with our read on it.