Rien Croonenborghs
Technical Lead & Principal Engineer
Personal Profile
Ruby on Rails engineer who likes building web applications from scratch and getting them into production. I spend my time writing code, mentoring developers, and working directly with product teams to figure out what actually needs to be built. I prefer straightforward communication and sensible planning over heavy process to ship reliable software on time.
Technical Skills
Core & Frameworks
Ruby on Rails, JS (React, Vue), SQL, HTML/CSS
Cloud & Infrastructure
AWS, Heroku, RESTful APIs, CI/CD, Git, System Design
Databases & Search
PostgreSQL, MySQL, MongoDB, Elasticsearch
Testing & Practices
RSpec, Cypress, TDD, Agile (Scrum, Kanban, Shape Up)
Secondary Languages
Java, PHP, Perl, Bash, C/C++
Work Experience
Technical Lead & Principal Engineer
Hnry · Wellington, New Zealand & Sydney, Australia
2022 - Present
- Technical Lead & Principal Engineer for Hnry’s Banking, Tax, and Platform teams, building and scaling the core financial infrastructure used by over 60,000 sole traders across Australia, New Zealand and the United Kingdom.
- Mentoring a small team of engineers and partnering with leadership to plan and deliver major product milestones.
Senior Software Engineer
Hatch Invest · Wellington, New Zealand
2021 - 2022
- Led the technical rollout of a virtual banking integration with FNZ, giving retail investors in New Zealand direct access to the US stock market.
- Built secure transaction processing and banking workflows that satisfied strict financial compliance rules.
Senior Software Engineer & Technical Lead
ecoPortal · Auckland, New Zealand
2014 - 2021
- Guided a team of 5 engineers building a SaaS platform for health, safety, and environmental compliance.
- Modernized the frontend architecture by phasing out legacy code and introducing a modern JavaScript framework.
- Slashed release cycles from 4 months down to 3 weeks by tightening up our testing, issue tracking, and deployment pipeline.
Senior Software Engineer
YouDo · Wellington, New Zealand
2010 - 2014
- Built B2B and B2C web apps for New Zealand's retail electricity market.
- Delivered customer-facing portals and back-office systems built to handle strict energy sector regulations.
- Cleaned up deployment pipelines and improved overall system reliability for core energy services.
Earlier software engineering roles available upon request.
Hobbies
Strength training. Fiddling with personal software projects. Photography. Juggling balls, rings, clubs and kendama. Hiking.