Constantin Metz

History

From Minecraft mods to the App Store

Self-taught, shipping software since school. The whole story, oldest first, with the names the rest of the site leaves out.

  1. Childhood

    Teaching myself to code

    HTML, CSS and JavaScript first, building pages for the fun of it. Then Java, by writing Minecraft mods: the first real programs, and the first time code had to work for someone else.

  2. 2018–2019

    Internships during school

    oliv newlab · Evolit Consulting · Hoffmann Eitle

    • oliv newlab: web development with Django.
    • Evolit Consulting in Vienna: a fleet-management tool in TypeScript and Angular.
    • Hoffmann Eitle, a patent law firm.

  3. Dec 2019 – Apr 2020

    Web services for a Minecraft network

    LuminuNET

    Still at school, I built the web side of the LuminuNET Minecraft network: one sign-in for the forum, the website and the game servers, a Vue component library for its sites, and key redemption.

    • A hand-rolled OpenID Connect provider (implicit flow) on the forum's legacy XenForo accounts, December 2019 to January 2020: consent screens, Redis rate limits, an RSA-4096 key pair per client, RS256 tokens.

    Case study: Originsoidc-server on GitHub key redemption on GitHub

  4. Feb 2020 – Oct 2021

    Intern, then developer, then senior developer

    adabay · Munich

    • Web development internships: the mobile site for Mammut, and an internal i18n tool built from scratch.
    • Part-time developer at 18, alongside school: a monorepo of React widgets with Storybook, sites on the Twill CMS, contributions to open source.
    • Senior Developer from April 2021: client architectures documented with arc42 and C4, server-side rendering with caching, introduced Storybook and Tailwind, upgraded TYPO3.

  5. 2020–2021

    Sequelize maintainers team

    Sequelize

    On the maintainers team of Sequelize, the SQL ORM for Node.js, while it moved to TypeScript: 13 pull requests (10 merged) and, in 2021, reviews of 28 pull requests by other contributors. The largest, #13710, moved the library's errors to TypeScript: +731 −616 across 41 files.

    Case study: Originssequelize#13710

  6. Nov 2021 – Sep 2023

    Senior Software Engineer

    DealerCenter Digital · Landshut

    • Frontend, backend and DevOps, on a modular architecture documented in C4.
    • An Nx monorepo for the internal tools.
    • Led an offline-capable PWA that keeps in-store kiosks and tablets in sync.
    • Merged several inventory systems into one cached service.
    • Faster, safer CI/CD.

  7. Oct 2023 – Sep 2026

    Software Engineer, Jira marketplace apps

    Appfire · remote

    • A large React app, Node.js services, and C#/.NET.
    • Introduced an Nx monorepo.
    • Aligned engineering practices across teams.
    • Part of a winning hackathon project.

  8. Mar 2025 – Oct 2026

    Zenarios, on my own

    Zenarios

    Alongside work, a financial planner for iPhone and Mac, designed and built alone: the simulation engine, the app, the design system, the website and the launch film. On the App Store since 2026.

    Case study: ZenariosZenarios on the App Store

  9. Since Oct 2026

    AI for industrial quoting

    Mercura (YC W25) · Munich

    Mercura automates quotes and orders for industrial distributors and manufacturers with AI.

2020

The site before this one

keimeno.party, 2020: Vue 2, neo-brutalist, bright green. It had no story and no About page, and without JavaScript it showed nothing. This site tries to do the opposite.

See it in the Wayback Machine ↗

keimeno.partyScreenshot to come

All workAbout