Full stack developer | contractor
[PHONE] +358 40 543 0157
[EMAIL] mikko.vaananen at gmail.com
[STATUS] Available for new engagements
Each of these clients brought a complex domain — electricity contracts, public transport ticketing, financial reporting, property management — and needed a developer who could understand the business, not just implement a specification. The domain knowledge that builds up over years of working inside an industry is what makes the difference between a feature that ships and a feature that actually solves the problem.
With over twenty years of production experience, I combine that domain fluency with a modern full-stack capability and AI-accelerated delivery that measurably compresses timelines — without adding risk. The result is clear communication throughout, and working software that holds up in production.
I'm Mikko Väänänen — a full-stack contractor with over two decades of production software experience across energy, transportation, finance, and property management. I've built customer-facing platforms for Finland's second-largest electricity distributor, contributed to an award-winning public transport app (Best Mobile Service, Slush 2018), and delivered financial tooling used daily by accountants and small businesses. Clients consistently describe the same pattern: I understand the business behind the ticket, not just the technical requirement, and I stay reliable when delivery pressure peaks.
I take a pragmatic approach — clear communication, no surprises, and solutions that solve real problems rather than tick boxes. I understand that good software starts and evolves with understanding customer needs and business requirements, and I work well in teams that value quality and openness, whether onsite or in a distributed remote setup.
My stack centres on React, React Native, Node.js, TypeScript, PostgreSQL, GraphQL, and AWS. I also fluently orchestrate AI coding agents — Claude Code and GitHub Copilot — across the full development lifecycle: code generation, automated review, iterative refactoring. This measurably compresses delivery timelines without sacrificing quality.
Based in Finland, I've worked remotely for years and am comfortable collaborating with distributed teams across different locations and time zones.
Ready to see what I can bring to your project? Review my project history to explore my experience across different domains and technologies. Let's discuss how I can help drive your next project forward.
Developing Kenno, a modern property management and enterprise resource planning (ERP) system, tailored for rental housing companies and property managers in Finland.
My role is to design and develop key modules of the system such as ledger, contracts management, invoicing, housing, and debt collection while developing both GraphQL and REST APIs to support seamless frontend and backend integration.
Developing and maintaining customer portal Aina for Elenia, the second largest distribution system operator in Finland. Aina is a platform for customers of Elenia to manage their electricity contracts and consumption.
My role was to design and develop new features such as a landing page with interactive widgets, combined graphs for consumption and production metering points, and energy price calculations. I also implemented new integrations for e.g., customer and metering data.
Redesigning a web application for a client in healthcare.
Maintained and developed a web application for a client in public sector for food import/export certifications.
Developed a web application for process industry. The application was used to monitor and control industrial processes by operators.
I developed e.g., a user interface for controlling sequences, a series of steps and conditions which can be used to automate industrial processes.
Developed and maintained an award-winning (Best Mobile Service in Android One category at Slush, 2018) HSL mobile application and its backend services. The HSL application integrated ticket purchasing and management, a journey planner, and personalized news into a beautiful app.
I focused especially on the ticket purchasing feature on the app and backend. I also took care of migrating from the old municipal regions to new ABCD zones in the HSL area in April 2019 on the HSL app and backend domain.
Maintained and developed Accountor Go, a financial web application and a related mobile app for SMBs. This was a part time role while working full time on another project.
As a single developer in this project I took care of the infrastructure, maintenance and development of the app as well as the support for the customers and accountants.
Maintained and developed Accountor Go, a financial web application and a related mobile app for SMBs.
As a single developer in this project I took care of the infrastructure, maintenance and development of the app as well as the support for the customers and accountants.
I developed content image support on top of the AOSP build system. This enabled our product programs and technical sales to create product variants for different markets and operators efficiently and easily.
I worked as a specialist in a number of high-profile integration projects that shaped the future of the whole S40 platform. I also developed a new build system for the S40 platform that was superior to the old one in terms of reliability, speed, efficiency, and features.
“Working with Mikko is easy. He is dedicated to his work and willing to go the extra mile when needed, because he always keeps the client’s end customer clearly in mind. A definite plus is his accumulated understanding of the energy sector and its related technical details and market. Long experience shows as a calm and confident approach to his work without compromising on efficiency."
"Mikon kanssa on helppo työskennellä. Hän on omistautunut työlleen ja on valmis venymään tarvittaessa, koska hänellä on aina myös asiakkaan loppuasiakas kirkkaana mielessä. Ehdottomana plussana karttunut ymmärrys energia-alasta ja siihen liittyvistä teknisistä yksityiskohdista ja markkinasta. Pitkän linjan kokemus näkyy rauhallisena ja varmana otteena työssään tehokkuudesta tinkimättä.”
“Mikko is one of the most experienced developers in the HSL mobile app team. He easily understands the business logic and puts that into code. He is easy to work with, talented in his field and very reliable. He finds solutions even under pressure and with very little sleep – like after a night when HSL converted into new zones. I highly recommend Mikko as a senior level developer.”
“In desperate need of a talented developer that documents both his code and the findings, people (non-devs) recommended Mikko to me. I decided to reach out to Mikko, and he jumped in instantly. Fast forward to results… I got easy to comprehend documentation, clean code and debriefing. I am very pleased and can easily recommend Mikko for senior level dev tasks.”