Our Story

Built for people who
live by the seasons.

Aurinko — Finnish for Sun — was born from a simple observation: human energy is seasonal. Your app should know that.

The Origin

A December run in Helsinki that changed everything.

In December 2024, a developer living in Helsinki opened his fitness app at 14:45. Sunset was in 15 minutes. The app suggested a 60-minute outdoor trail run.

The temperature was -8°C. The trail was icy. He had eaten once that day (typical dark-winter appetite suppression). His HRV was 18% below baseline.

The app had no idea. It just wanted its checkbox ticked.

That's when Aurinko was born — not as an idea, but as a frustration.

Helsinki · December

Sunrise
09:23
Sunset
15:10
Daylight
5h 47m
Temperature
-8°C

What Aurinko would have said:

"Sunset is in 15 minutes. It's -8°C. Your HRV is low. Perfect day for 30-min indoor yoga and a warm meal."

Our Philosophy

Three principles. One app.

01

Environment First

Every recommendation starts with where you are and what the sky looks like. Not yesterday's steps. Not a static calendar. The world, right now.

02

30 Seconds a Day

We designed for the person with 30 seconds, not 30 minutes. The check-in is 3 taps. The plan is one sentence. The insight compounds over time.

03

No Perfect Weather

We don't optimize for summer conditions. We optimize for your conditions, today. Bad weather isn't an excuse — it's a different kind of opportunity.

The Technology

Modern infrastructure,
built to last.

Aurinko is built as a small, efficient distributed system — designed to run under €15/month until 500 users, without sacrificing quality or reliability.

Backend Go 1.26, net/http, GORM, PostgreSQL
Web Dashboard React 19, Vite, Tailwind, TanStack
Mobile Kotlin, Jetpack Compose, Room DB
AI/ML Python, scikit-learn, LLM APIs
Infra Docker, Caddy, Cloudflare, Grafana LGTM
External Data Open-Meteo API, FMI Open API

Design Principles

Privacy-first: location never stored, only processed
Cost-efficient: designed to scale on minimal infrastructure
Open-first: built on open APIs and open-source tools
Offline-capable: core features work without internet

Development Roadmap

7 phases from foundation to global expansion. Currently in Phase 0.

View on GitHub
🇫🇮

Why Finland

Aurinko means Sun in Finnish.

Finland is where seasonal extremes are most felt. From 21-hour summer days to 5-hour winter darkness — Finnish people have developed a unique relationship with light that shapes everything from culture to architecture to wellness.

We named the app after the sun because the sun is the most important variable in human wellness that no fitness app accounts for. Aurinko fixes that — for everyone, everywhere.

Ready to train with the world?

The first step is a 30-second check-in. The result is a fitness practice that actually fits your life, season by season.

Get Started Free