Tuukka Haapasalo

IQM Resonance

The system through which IQM’s customers and researchers run jobs on quantum computers. Started as a public cloud service and has grown into the shared front door for all of IQM’s machines. In 2026 IQM Resonance has three machines, the largest at 54 qubits.

On the project from the start of implementation: I have co-designed the architecture and built a large part of the backend that queues and dispatches quantum jobs to the machines, as well as the user interfaces. The architecture is largely the work of a colleague and me. The server, originally written in Python, was replaced with Rust during the project for performance and maintainability. Team of around ten.

• Rust
• axum
• PostgreSQL
• React
• TypeScript
• Python

Telia Dot

A fully digital mobile operator built for Telia from the ground up, running on Telia’s cellular network and backend systems. The product is a mobile subscription managed entirely through the customer app.

On the project from the start of implementation, in a team of around fifteen. We designed the initial architecture together; after that people came and went, and I stayed. Over the years I became the developer who knew the whole system and steered where its architecture went. I worked on nearly every part of it: subscription provisioning into the network, an event-execution engine with guaranteed delivery and automatic retries, subscription billing, integrations with tens of legacy backend systems, the internal customer-service tool and the customer-facing mobile app.

• Node.js
• TypeScript
• React
• React Native

Kesko — Caara Leasing

Mobile app and its backend services for Kesko’s Caara Leasing customers, built end to end by a team of two. Followed by the Android version of Kesko’s Volkswagen Owner app.

• TypeScript
• Node.js
• React Native
• Android

OP — Osta laskulla

Architect and developer on OP’s invoice and instalment payment button for online checkouts. Backend in Java and Kotlin, purchase flow UI in React. The main challenge was fitting the bank’s core systems behind a smooth checkout experience.

• Java
• Kotlin
• React

Fintoto backend systems

Backend development in a small team for Fintoto, the Finnish horse-race betting operator. The most demanding piece was a distributed bet-prioritisation service (Scala, Hazelcast), which I designed and built together with one other developer: we buffered the bets from several servers into one shared queue and fed them on to the various backend systems at a limited rate, so that every user got the same share of the bandwidth and no backend was pushed past its capacity. Also built internal tools and worked on the Fintoto web system.

• Scala
• Hazelcast
• Java

Fintoto Toto-mobiili

Designed the architecture and built most of Fintoto’s HTML5 mobile betting app — among the first to offer live video on every common smartphone of the day. Best HTML5 consumer service in the Best Mobile Service in Finland 2013 awards (Teleforum).

• JavaScript

OP file transfer service

Team lead and developer on a file-transfer service for small businesses in OP’s online bank. Coordinated the team’s work and the changes needed across the bank’s systems, and wrote code alongside the team.

• Java
• Spring

OP-Mobiili and S-Pankki mobile

Android versions of OP’s and S-Pankki’s mobile banking apps. On OP-Mobiili, fixed critical barcode-scanning problems late in the project.

• Android