# What connects Soft Dev Oy and the ProApp startup?

Leonid Kachuliak was system architect and team leader at the ProApp startup in 2020–2023; Soft Dev Oy worked with ProApp in 2023–2025.

- URL: https://softdev.fi/en/blog/soft-dev-and-proapp
- Author: Leonid Kachuliak, CEO — https://www.linkedin.com/in/leonid-kachuliak
- Published: 2026-10-25
- Updated: 2026-10-25
- Section: Soft Dev — https://softdev.fi/en/blog/soft-dev
- Language: en-GB
- Translation: https://softdev.fi/blogi/soft-dev-ja-proapp
- Source: ProApp – home page (checked 25.10.2026) — https://proapp.fi
- Source: ProApp – Short in English (checked 25.10.2026) — https://proapp.fi/short-in-english/
- Source: Leonid Kachuliak – LinkedIn profile, Experience section (checked 25.10.2026) — https://www.linkedin.com/in/leonid-kachuliak
- Source: Soft Dev: ten years of software development and more than 150 projects — https://softdev.fi/en/blog/soft-dev-ten-years (2026-10-12)

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## In brief

ProApp is a Finnish startup that builds a SaaS system for managing construction projects, designed for subcontractors, main contractors and clients. According to the company, two periods connect it with ProApp: from February 2020 to June 2023, Leonid Kachuliak worked at ProApp Oy as a private individual, as system architect and team leader, and from February 2023 to December 2025 the company Soft Dev Oy worked with ProApp.

The article “[Soft Dev: ten years of software development and more than 150 projects](/en/blog/soft-dev-ten-years)” mentions ProApp in a single line. This article goes into more detail: what ProApp is, in what role the founder of Soft Dev Oy worked there, and what Soft Dev Oy did once the company itself took on the project.

## What is ProApp?

ProApp is a construction project management system that connects work on site with project management. According to [proapp.fi](https://proapp.fi) (as of 25 October 2026), workers log hours, completed work and documentation from their phones directly on site, and supervisors follow progress in real time. Drawings, photos and project documents are kept in one place, and everyone on site has the latest versions at hand. The system is designed for subcontractors, main contractors and clients; the ProApp apps are available on the App Store and Google Play. ProApp is a product of ProApp Oy.

## What were Leonid Kachuliak's responsibilities at ProApp?

According to the company, from February 2020 to June 2023 Leonid Kachuliak worked at ProApp Oy as System Architect & Team Leader. He worked there as a private individual, as an employee of ProApp Oy: Soft Dev Oy did not exist until February 2023. As system architect he designed the system architecture and planned the whole project, from the data model to the web platform; as team leader he led the development team. The same title and dates appear on his [LinkedIn profile](https://www.linkedin.com/in/leonid-kachuliak).

Besides design, Leonid Kachuliak was responsible for rolling out ProApp and training the people who use it. According to the company, in 2020–2023 he visited many construction sites in different cities across Finland, installed the ProApp iOS and Android apps together with the workers and showed them how to use the apps in their daily work. In offices he trained the staff who work with the system's data, including accountants. The same person who designed the system also put it into use himself, on site and in the office.

Our observation: when the system architect and the team leader are the same person, decisions about how the system is built and decisions about the order in which it is built do not pull in different directions. The architecture and the work plan stay in the same hands.

## What did the ProApp team work on?

According to the company, the team led by Leonid Kachuliak worked on every part of the ProApp system:

- the server infrastructure the system runs on;
- the backend: system logic and data handling;
- the frontend and the web platform for project managers;
- the iOS and Android mobile apps used on site.

The team handled the whole path of the data, from an entry on a worker's phone to the server and the project manager's screen. The system's features are described on the ProApp website.

## What did Soft Dev Oy do for ProApp?

From February 2023, when Soft Dev Oy was founded, work on ProApp was done by the company rather than by Leonid Kachuliak as an employee of ProApp Oy. According to the company, Soft Dev Oy handled development and support of ProApp in 2023–2024 and only support in 2025, and its work with ProApp ended in December 2025. From February to June 2023 the two periods overlapped: Soft Dev Oy was already operating, and Leonid Kachuliak still held his position at ProApp Oy.

| Period | Who worked with ProApp | In what role | What was done |
| --- | --- | --- | --- |
| February 2020 – June 2023 | Leonid Kachuliak | private individual, ProApp Oy employee: System Architect & Team Leader | system architecture, project planning, team leadership, rollout and staff training |
| February 2023 – December 2024 | Soft Dev Oy | company | development and support |
| January – December 2025 | Soft Dev Oy | company | support only, no new development |
| From January 2026 | — | — | Soft Dev Oy does not work with ProApp |

The table shows that from February 2020 to December 2025 the same person was connected with ProApp: first as an employee of ProApp Oy, then as head of Soft Dev Oy.

## Why does the ProApp experience matter to Soft Dev Oy today?

Our observation: a system that clients use does not end at handover; it is developed and supported for years after launch. With ProApp this shows in the dates: the last of almost six years went entirely into supporting a system that was already running. Soft Dev Oy takes this experience into its own products.

Today Soft Dev Oy builds its own products on the [Axis Ordo](/en/blog/axis-ordo-ao-platform) platform and takes on custom work only for large projects in three areas: web applications, mobile apps and server infrastructure. These are the same areas the team worked in at ProApp. The kinds of projects Soft Dev Oy accepts are described on the [Custom development](/en/development) page.

## Where is the line between ProApp and Soft Dev Oy?

ProApp is a startup and product of ProApp Oy, not of Soft Dev Oy. Soft Dev Oy does not sell or represent ProApp, and has not worked on it since January 2026. Questions about the system, pricing and onboarding should go to ProApp through [proapp.fi](https://proapp.fi). This article describes only the role of Leonid Kachuliak and Soft Dev Oy in the project: in what capacity, what was done and when. We do not name ProApp's clients or the details of their work: they are another company's clients.

## So what connects Soft Dev Oy and ProApp?

The connection consists of two periods. According to the company, from February 2020 to June 2023 Soft Dev Oy's founder Leonid Kachuliak worked at ProApp Oy as system architect and team leader, and from February 2023 to December 2025 Soft Dev Oy itself worked with ProApp: first on development and support, then on support only. If you need a system of this scale, describe your task on the [Contact](/en/contact) page.

## Frequently asked questions

### Does ProApp belong to Soft Dev Oy?

No. ProApp is a startup and product of ProApp Oy. According to the company, Leonid Kachuliak worked at ProApp Oy as system architect and team leader from February 2020 to June 2023, and Soft Dev Oy handled development and support of ProApp from February 2023 to December 2025. Soft Dev Oy does not sell the system; information about ProApp, pricing and onboarding is on proapp.fi.

### Is ProApp still in use?

Yes. As of 25 October 2026 the proapp.fi website is live, and the ProApp apps are available on the App Store and Google Play. Soft Dev Oy no longer takes part in work on ProApp: the last stage, support of the system, ended in December 2025. Questions about how the system works today should go to ProApp Oy through its website.

### Can Soft Dev Oy build a similar system for another company?

Yes, this is the scale of work Soft Dev Oy takes on as custom development. Today the company accepts only large projects in three areas: web applications, mobile apps and server infrastructure. According to the company, the team handles a project end to end, from design and servers to iOS and Android apps. You can describe your task on the Contact page.

## Sources

- [ProApp – home page (checked 25.10.2026)](https://proapp.fi)
- [ProApp – Short in English (checked 25.10.2026)](https://proapp.fi/short-in-english/)
- [Leonid Kachuliak – LinkedIn profile, Experience section (checked 25.10.2026)](https://www.linkedin.com/in/leonid-kachuliak)
- [Soft Dev: ten years of software development and more than 150 projects](https://softdev.fi/en/blog/soft-dev-ten-years) — 2026-10-12