Hans Otto Wirtz

CTO · Software Engineer · Founder

hansottowirtz@gmail.com · hansottowirtz.be · github.com/hansottowirtz · linkedin.com/in/hansottowirtz

Software engineer and entrepreneur with 7 years of experience as CTO and co-founder of BubblyDoo, scaling the company from inception to €5M in revenue. Deep expertise in web platform technologies. Comfortable across the full stack, from building complicated frontends and backends to managing teams, handling operations and strategy. Passionate about solving hard technical problems, going deep, and getting things done. I love beautiful APIs. Looking to get out of my comfort zone in next role.

Experience

BubblyDoo

2019 – 2026

CTO, Co-Founder

  • Built tech to scale from 0 to €5M and 175k books per year
  • Hired and led team of 4 software engineers
  • Involved in every aspect of running a startup
  • Launched in 25+ countries, 10+ printing integrations

Ottomatisch

2015 – present

Self-employed

  • Made websites for small businesses during studies

Projects

BubblyDoo Personalization Platform

  • Platform that powers all BubblyDoo's personalization and rendering
  • Renderer built on web technologies, highly optimized for performance
  • Consists of renderer, visual editor, Photoshop plugin, backends, etc.
  • Foundations open sourced: react-done-tracker, uxp-toolkit
  • Improved and rewritten with learnings of 7 years

BubblyDoo Website & Backend

  • Millions of visitors every year
  • Built on Next.js and Cloudflare Workers
  • Data analysis with dbt, Looker Studio and PostHog

Education

Antwerp Management School, ESSCA Shanghai

2019 – 2020

Master of Global Management — China-Europe Business

Magna cum laude

University of Antwerp

2018 – 2019

Master of Science — Computer Engineering

Did not finish

National University of Singapore

2019

Exchange semester

University of Antwerp

2015 – 2018

Bachelor of Science — Computer Engineering

Cum laude

Technologies

Exceptional: Web Platform, Javascript, Typescript, React, Next.js, State management, Cloudflare Workers & Platform, AWS Lambda, Node.js, Bundlers, Puppeteer
Very good: Agentic engineering, PostgreSQL, dbt, Git, Docker, CI/CD, Observability, Testing methodologies, Vitest, Ruby, Angular, Vue, Linux sysadmin
Good: Python, C, Queues, Durable workflows, CAD, PCB design

Languages

  • Dutch: native
  • English: fluent
  • Spanish: intermediate
  • French: intermediate
  • Mandarin Chinese: lower intermediate

Interests

Cooking, Reading, Learning, Politics, Economics, History, Being creative, Design, Piano, 3D printing, DIY, Running, Trains, Education, Future of Europe, China, Making videos, Society & technology, Writing, Coffee

Recognitions

Forbes 30 under 302025
Deloitte Fast 50 Belgium2024

9th place, with BubblyDoo