HSG IT FinlandSoftware Development in Finland —
Write It Once, Ship It Everywhere
Senior product engineers who build software for a living and then run it. We put shared logic in a pure Rust core and ship it to the browser and to native mobile from the same source — the architecture behind our own products, not a slide. Same timezone, EU-GDPR, typical start in 2 weeks.
Product Engineering, End to End
Web Applications
React and TypeScript front ends that hold up under real use: routing, state, accessibility, and the unglamorous parts — error boundaries, offline behaviour, and a build that stays fast as the app grows.
Native & Cross-Platform Mobile
Kotlin on Android, Swift on iOS, and Flutter or React Native where a shared UI layer earns its keep. Native where it matters — background audio, push, permissions, and the OS behaviours a webview cannot reach.
Shared Logic in Rust
The computation every platform needs, written once as a pure core with no DOM and no platform APIs, then compiled to WebAssembly for the browser and to native libraries for mobile. One implementation, one test suite, no drift.
Backends & APIs
Python and Rust services, REST and WebSocket APIs, relational data modelling that survives the second year, background jobs, and the migrations to get there from whatever you have now.
Tests That Can Fail
We are a test-automation firm first, so the code we write arrives with coverage that actually bites — unit, API, end-to-end and accessibility — wired into CI rather than run by hand before a release.
Ship and Operate
Containerised deployment, infrastructure as code, observability from day one, and a rollback story you have rehearsed. Building it is half the job; the half that wakes you at night is the other one.
We Run What We Build
The clearest thing we can show you is a product of our own. WebCallHub is a click-to-call platform with a React web app, native Android and iOS clients, a Python backend, and real-time voice underneath all of it.
Its shared logic lives in a Rust core with no DOM and no platform dependencies. The browser gets it compiled to WebAssembly; the mobile apps get it compiled to native libraries. When a rule changes, it changes in one place — the alternative is the same logic written three times and wrong in two of them by the second year.
That is not an opinion we can only assert. It is the codebase we maintain.
How We Engage
Codebase Orientation
We read the code, run whatever tests exist, and hand back a written map: how the system fits together, what is risky, and the order we would fix it. Yours whether or not you continue.
Book OrientationBuild the Product
Web, mobile and backend delivered as one piece of work, with the tests and the deployment path included. Scoped and priced after we have read the ground, never before.
Scope a BuildEmbedded Engineer
A senior developer inside your team — your repo, your sprints, your review process. Everything written stays yours.
Get QuoteSoftware Development FAQ
What software development services does HSG IT offer in Finland?
Product engineering end to end: React and TypeScript web apps, native and cross-platform mobile (Kotlin, Swift, Flutter, React Native), Python and Rust backends, REST and WebSocket APIs, Postgres data modelling, containerised deployment, and the test automation to keep it honest. We work as an embedded team inside yours or as a fixed-scope build.
How do you avoid writing the same logic three times for web, iOS and Android?
We put the shared computation in a pure Rust core with no DOM and no platform APIs, then ship it through two pipelines: compiled to WebAssembly and wrapped as a Web Component for the web, and compiled to native libraries or bound through UniFFI for iOS and Android. One implementation, one set of tests, three platforms that cannot drift apart. It is the architecture we use in our own products.
Do you build mobile apps as well as web?
Yes, and natively rather than in a webview. We ship Kotlin on Android and Swift on iOS, and we work in Flutter and React Native where a shared UI layer earns its keep. Mobile frameworks cannot consume a Web Component, so they get the compiled native library instead of a wrapped browser widget.
Can you take over an existing codebase?
Yes. A typical start is a two-week orientation: we read the code, run whatever tests exist, and come back with a written map of the system, the risks we found and the order we would address them. You get that document whether or not you continue with us.
How do you work with our in-house developers?
In your repository, on your sprints, in your review process. We are engineers you add to a team, not a vendor behind a contract boundary. Everything we write is reviewed by your people and stays yours.
Where are your engineers based?
HSG IT Services Oy is a Finnish company based in Helsinki, working in Finnish business hours across Finland, the Nordics and the wider EU. EU-resident staffing is available where data protection or procurement rules require it.
Have something to build?
Book a free 30-minute call. Describe what you are trying to ship and we will tell you what we would do first — and whether we are the right people for it.