Onni Rantanen

Full Stack Developer
Espoo, Finland
+358 40 417 9331


Broad knowledge in many aspects of software development, specializing in full stack web development.

Fast and eager learner—a new language, technology or stack is never an obstacle.

Fluent speaker and writer of Finnish and English.

Key Skills

Full Stack Web Development

JavaScript, TypeScript, React, Angular, Node.js, C#, Java

Test Automation

Jest, Jasmine, NUnit


Docker, CI / CD, AWS, Google Cloud


Linux, Shell Scripting, Git

Work Experience


September 2022 - Present

TypeScript, Angular, C#, ASP.NET Core, PostgreSQL, Snowflake, AWS

  • Worked on design, development, and automated testing of a retail data analytics SaaS.
  • Collaborated on the design of a shared cloud architecture, including a large migration effort to a new Snowflake-based data warehouse.

Espoo City Library

September 2020 - August 2022

TypeScript, React, Node.js, MySQL, Java

  • Developed a large-scale full stack web application for library staff from the ground up, with companion apps for desktop and Android.
  • Created an RFID-based inventory tracking & management system for library materials.
  • Streamlined & automated shipment reception and processing into library systems.
  • Implemented extensive search system, highly optimized for both query speed and user experience.


Computer Science, University of Helsinki

2017 - 2020

General Upper Secondary Education, Uudenkaupungin lukio

2014 - 2017