Finnish National Agency for Education (Opetushallitus)

Before 2018, a person's educational history lived in scattered systems across schools, institutions, and authorities. A law that took effect that year obliged education providers to record study completions in one national data store and made OPH responsible for how it works.

KOSKI is the system built to meet that obligation. Most studies completed anywhere in Finland are now modeled inside it, feeding everything from funding calculations to a citizen checking their own record while applying to study. KOSKI functions as the backbone of Finnish education data.

The hard part was never the plumbing.

Finnish education contains a great variety of study rights and progression rules, and all of it had to be captured faithfully enough to drive real decisions about money and eligibility.

Reaktor took a schema-first approach, combining PostgreSQL JSONB storage with Scala schemas that describe and validate every shape of data the system accepts. That foundation is why the data stays high quality at scale, and why the model has kept growing for years without collapsing under its own complexity.

The architecture is deliberately simple, a modular monolith on a durable stack of React, TypeScript, Scala, and PostgreSQL, runnable end-to-end on a single developer's machine. Quality comes from tooling rather than a separate QA team: extensive unit, integration, and browser tests, data model backward compatibility tests, API docs tied to the code, and a release pipeline where small changes reach production several times a day once automated checks pass.

Privacy was designed in from the start, with people identified by learner numbers rather than social security numbers, and citizens able to see exactly which authority accessed their record and when.

Let's say you've studied in Finland at any point since the start of 2018, KOSKI's first day of record. Any school, anywhere. KOSKI contains your study records from elementary school to matriculation exam grades and university degrees. You can view your own verified study records and share them by way of a single link or, even better, give consent to any organization that has deployed a so-called MyData integration into KOSKI to use your information automatically, for example, when buying a public transport ticket with a student discount.

Authorities draw on the same source for organizing education, granting benefits, calculating funding, and research. A legally defined disclosure service offers information for many governmental organizations with a legal right of access, including Kela, Migri, Statistics Finland, and the Ministry of Education and Culture.

The documentation, the code, and even a shared test environment are public, in keeping with OPH's commitment to openness.

The KOSKI project is regularly showcased both in Finland and internationally.

KOSKI is one of the most cost-effective critical systems built in Finnish public administration. It’s regularly presented as an example of what a long-lived public system can be when a small, capable team and an engaged client build it together and with precision from the start.

It’s a fully custom-built, hand-crafted, artisan-coded system based on legislation. Changes, additions, and fixes are fast and inexpensive to make.

→ Designing and building the system in close collaboration with the client
→ Data modeling
→ System design, UX, and UI design
→ Data architecture on PostgreSQL JSONB and Scala schemas
→ Software and integration development
→ Disclosure service
→ Testing, CI/CD, monitoring, and incident-management tooling
→ Continuous services
→ Broad-based consulting