Alan Geirnaert
Software Engineer

Alan
Geirnaert

I build production software, and I'm working my way toward the scientific end of it: simulation, satellite data, and computational tools for planetary science.

Based in France.

See the work
Alan Geirnaert
exoplanets analyzed
6,100+
hackathon wins and nominations
4
countries I've shipped from
2
01 - About

Software where engineering meets science

My background is in production full-stack software engineering, but I'm increasingly focused on scientific computing, Earth observation, simulation, and computational tools for planetary and space science.

Scientific computing

C++ and Python for simulation and numerical methods: Barnes-Hut N-body systems, OpenMP multithreading, and analysis of real scientific datasets.

Earth observation and geospatial

Satellite imagery, raster pipelines, GIS tooling and environmental analysis with Sentinel data, MapLibre, and custom geospatial systems.

Production software

Full-stack production systems in Angular, Next.js, Node.js and Express, on MongoDB and PostgreSQL, with WebSockets, authentication, and typed contracts.

AI and retrieval

RAG pipelines end to end: embeddings, vector search, ranking, and source-linked answers for research-focused retrieval.

What I work with

Core

TypeScript · Angular · Next.js · Node.js

Backend

Express · FastAPI · REST · WebSockets · JWT auth · Go

Scientific

C++ · Python · OpenMP · Barnes-Hut · Numerical simulation

Geospatial

MapLibre · Sentinel-1/2 · Raster pipelines · GIS · Plotly

AI / Data

RAG · Embeddings · Vector search · Groq · Scikit-learn

Databases

MongoDB · PostgreSQL · Prisma

DevOps

Docker · GitHub Actions · Vercel · CI/CD

Testing

Jest · Vitest · Zod · Joi · Sentry

02 - Projects

Things I've built

Simulation, Earth observation, and retrieval systems built on real scientific datasets, plus a few production tools.

Best Data Visualization, Codédex 2026

Goldilocks

A scrollytelling data visualization built on the NASA Exoplanet Archive. I wrote a habitability scoring algorithm in Python that ranks 6,100+ exoplanets on several criteria, then wrapped the results in an interactive 3D story so you can actually explore them.

  • Python
  • Scikit-learn
  • Next.js
  • Three.js (GLSL)
  • Data Science

EntropyCosmos

A 3D N-body gravitational simulator modeling 1,000 celestial bodies in C++ and Python, using the Barnes-Hut algorithm for O(N log N) force computation, OpenMP multithreading, and 3D trajectory visualization.

  • C++
  • Python
  • Barnes-Hut
  • OpenMP
  • Pandas

Planetary Solutions for Earth

An Earth-observation mapping platform built for a Swiss environmental non-profit, layering satellite and demographic data over the Philippines. I serve custom raster tiles natively from Next.js, with 10m land cover fragmentation, Sentinel-5P nitrogen dioxide concentrations, 2020 population density, and public transport stops.

  • MapLibre GL
  • Raster Tiles
  • Sentinel-5P
  • GIS
  • Next.js

Papermind

Research infrastructure for scientific literature: a search engine running a full RAG pipeline of ingestion, embedding, vector search on MongoDB Atlas, query re-ranking, and source-linked answers. Built around a research UX that emphasizes filtering, trust, and reproducibility.

  • Next.js
  • MongoDB
  • Embeddings
  • Groq AI

GitPortal

A place to put your GitHub repositories in front of people who might want to help build them. I made it because finding contributors for a side project is harder than it should be.

  • Next.js
  • TypeScript
  • MongoDB
  • Groq AI
03 - Experience

Where I've worked

Shipping production code and running technical programs, across France, Switzerland, and the US.

Dec 2024 - PresentNow

Full-Stack Software Developer

App'Ines · Remote, France

Production platform work on a remote, distributed French engineering team.

  • Ship production features on a platform with 67,000+ registered healthcare professionals, and own them through deployment and incident follow-up
  • Built a real-time messaging feature over WebSockets, from connection handling and reconnection to delivery state in the UI
  • Built and deployed an internal dashboard with Angular + Ionic (Capacitor): JWT auth, role-based guards, secure token refresh, and protected routing
  • Designed REST APIs in Node.js/Express/MongoDB with typed DTOs, request validation, and contracts shared across client and server, cutting runtime errors
  • Refactored the frontend into reusable accessible components with route-level code splitting, improving load performance and maintainability
Oct 2025 - PresentNow

Software Engineer

PS4E · Remote, Lucerne, Switzerland

Sole developer for a Swiss environmental non-profit building open Earth-observation tools.

  • Built and maintain Planetary Solutions for Earth, a live Next.js mapping platform serving satellite-derived environmental data for the Philippines
  • Implemented custom raster tile serving natively through Next.js API routes, removing the need for external tile infrastructure
  • Integrated Sentinel-5P atmospheric data, 10m land cover fragmentation, population density and public transport layers over MapLibre GL
  • Currently building an educational platform for Earth observation, code and satellite data
Nov 2025 - Jan 2026

Head of Technical Program Management

SSIP · Hybrid, Lucerne, Switzerland

Technical and program leadership across the European space innovation ecosystem.

  • Led development of the official SSIP web platform (public pages, internal coordination tools for events and analytics)
  • Key contributor to ActInSpace Switzerland 2026 (Lucerne), a CNES and ESA-backed hackathon, across technology, operations and program delivery
  • Translated executive strategy into operational programs, platform roadmaps, and team workflows
Jul 2024 - Sep 2024

Software Engineer

Headstarter AI · Remote, USA

AI feature work in a fast-paced US remote engineering environment.

  • Built AI features using RAG and embeddings for knowledge-aware responses
  • Developed data pipelines and evaluation scripts; profiled latency and improved prompt consistency across environments
04 - Recognition

Awards and appearances

Hackathon results, mentoring and judging roles, talks I've given, and community features.

05 - Contact

Get in touch

If you're working on scientific software, Earth observation, simulation, space technology, or research infrastructure, I'd like to hear from you.

What's this about?

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Emailpro.geirnaert.alan@gmail.com
Based inFrance
GitHubalangnt
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© 2026 Alan Geirnaert