Mitchell Quitz

Rotterdam, the NetherlandsFull stack developer at AllesOnline

Selected work

04 items

scam.org

A reputation checker for domains, phone numbers, IBANs, email addresses, files and plain text, weighted across a stack of external sources. I built the Python service behind it: every provider queried at once with asyncio, each on its own timeout, results cached in Redis.

Stack
Python / FastAPI
Made
at AllesOnline

Pera Pera Café

A turn-based, multi-device conversation game for two or more players learning Japanese or Dutch. NestJS holds the session state and pushes it to every device over WebSockets, with Prisma on Postgres behind that. Dockerised with CI/CD.

Stack
TypeScript / NestJS / React
Made
in my own time

Library Card

A headless site for Library Card, the band I play guitar in. Laravel and Filament provide an admin for tour dates, music, videos and merch. Next.js renders the frontend with the App Router.

Stack
PHP / Laravel / TypeScript / Next.js
Made
in my own time

Segment

An integration service that keeps a coaching platform and a multi-entity CRM in sync. It was still speaking SOAP. Moving it to REST over OAuth2 and batching the queries cut API calls by 96.5%.

Stack
PHP / Laravel
Made
at AllesOnline

Skill overview

Languages
PHP · Python · TypeScript
Backend
Laravel · Filament · FastAPI · NestJS
Frontend
React · Next.js · Tailwind
Data
PostgreSQL · MySQL · Redis · Elasticsearch
Testing
Pest · PHPUnit · pytest · Jest
Tooling
Docker · Jira · Claude Code

About

I came to software late. I studied music first, then spent my twenties booking shows for a living, which taught me more about deadlines, logistics and people changing their minds at 17:00 during load-in than any course has since. I started HBO ICT part time in 2021, was hired as a developer in my second year, and graduated with a BSc in January 2025.

Since 2022 I have been building full stack web applications at AllesOnline. Most have a Laravel backend and a frontend built in either Next.js or React with TypeScript. When something would be more complicated to solve in Laravel, Python and FastAPI are used instead.

The things I build outside work usually start close to home. While studying Japanese I noticed my study group lacked a tool for asking each other questions in the language, so I made one. My band had no presence online, so I built them a site with a CMS they can manage themselves.