Startup CTO  ·  Game Developer  ·  Full-Stack Engineer

Hi, I'm Christoph.

Game developer turned startup CTO — I co-founded SellPilot and shipped titles to Steam, iOS and Android, building everything full-stack.

SellPilot
ErnieApp
IE University
Steam
Gravora
Google Play
App Store
Westnetz
Laser Chess
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Five countries. One constant.

I grew up between Italy, Germany, Norway and Portugal, and landed in Madrid for university — which explains both the languages and the tendency to adapt fast. Chess was the thread through all of it; I still compete at 2400 ELO, top 1000 on chess.com.

I started building games as a kid, just for fun — eventually shipped Gravora to Steam and Laser Chess to iOS and Android. That same drive became SellPilot, where I'm CTO and build the whole stack.

5 Spoken languages
500+ Users
20+ Projects built
Christoph Rintz
Education
BCSAI — Computer Science & AI
IE University  ·  Madrid 2024 — Present

Bachelor's covering algorithms, machine learning, systems programming, databases and AI — studied in English in Madrid. GPA 8.91 / 10.

Abitur — German High School Diploma
German School of Lisbon  ·  Portugal 2024

Final grade 1.8 (German scale: 1.0 is highest). Grew up attending schools across Italy, Germany, Norway and Portugal.

Experience
CTO & Co-Founder
SellPilot  ·  Madrid 2024 — Present

Building the full product solo — React Native app, Node.js backend, Firebase & PostgreSQL. 500+ beta users. In investment discussions with Winterberg Group.

Part-Time Developer
ErnieApp  ·  Lisbon & Madrid Jun 2022 — Present

AI-powered localization pipeline, frontend features, and building the marketplace UI from scratch.

Software Intern
Westnetz (RWE Group)  ·  Germany May – Jun 2022

Built internal tooling and worked on energy grid software for one of Germany's largest energy networks.

Technical Stack
Python Three.js JavaScript Git TypeScript scikit-learn React Native PostgreSQL Node.js GLSL React C Godot Django Firebase Unity Java Azure Unreal Engine Railway Solidity
Featured Projects

Games, simulations, tools & research

Let's Connect

Open to opportunities, collaborations, and interesting conversations.

  +351 969 244 176   Madrid, Spain
Christoph.
Startup CTO  |  Game Developer  |  Full-Stack Engineer

Christoph Rintz

Resume

Hands-on startup CTO and software engineer experienced in building, deploying, and maintaining production applications, games, and AI-driven systems. Strong background in Python, C++, Java, and React Native, with real-world experience in data security, localization, scalable development, and a constant drive to learn new languages and technologies.

Key Achievements

CTO of SellPilot

Development and Maintenance of a full-scale app and web platform for the startup SellPilot

Frontend Dev – ErnieApp Marketplace

Built and shipped frontend features for the ErnieApp marketplace platform

Venture Bootcamp Success

Secured 3rd place at IE venture bootcamp (Spain)

ErnieApp (Privacy & Ads)

Worked on privacy, security, and growth-related product work

AI Software Development

Developed AI tool predicting weather impacts (95% accuracy)

Game Development

Built and published multiple 2D and 3D games using Godot, Unity and Unreal

Experience

CTO – SellPilot
Madrid Present
Built and maintained a full-scale production app and web platform.
ErnieApp
Lisbon & Madrid Jun 2022 – Present
Frontend Dev

Built and maintained marketplace UI with React. Developed components and user flows, collaborating closely with the product team to ship new features.

Localization

Built an AI-powered pipeline to fully localize the app into German and Spanish, managing end-to-end translation and linguistic accuracy.

Privacy & Security

Worked on privacy, security, and data collection features. Contributed to app design improvements and customer acquisition product work.

3rd Place - Venture Bootcamp IE
Madrid, Spain February 2025
Developed a startup app currently under development with my team. Mentored by industry experts; pitched to investors and refined scaling strategy.
NTT Hackathon - IE University
Madrid, Spain February 2025
Developed an AI-powered software to predict future weather patterns and impacts for NTT DATA.
4th Place - Venture Bootcamp IE
Madrid, Spain September 2024 – October 2024
Developed a startup app; refined business and scaling strategies with mentors.
Internship at Westnetz
Saffig, Germany May 2022 – June 2022
Exposure to energy informatics, engineering, and business operations. Completed a full course on programming with Python.

Languages

English
Native
German
Native
Norwegian
Proficient
Portuguese
Advanced
Spanish
Advanced

Education

Bachelor in Computer Science and Artificial Intelligence
IE University (IEU), Madrid, Spain January 2024 – Present
GPA: 8.91 / 10.00
Coursework: Data Analysis, Algorithms, Databases, ML, Blockchain

Skills

Development

  • Proficient in Python, C++, Java, and C
  • Game development with Godot, Unity, Unreal
  • Web development (React, JavaScript, HTML/CSS)
  • React Native for mobile applications
  • Version control with Git/GitHub

Tools & Software

  • IDEs: Cursor, VS Code, IntelliJ
  • Advanced MS Office Suite
  • Video editing (Adobe, Filmora)
  • Firebase & database integration
  • PC building & IT troubleshooting

Technical Skills

  • Data security & privacy implementation
  • App localization & translation systems
  • AI/ML model development
  • Cloud platforms & deployment
  • Production app maintenance

Contact

All Projects
Games
Simulations
Academic