David Lepaux
Engineering Lead
I turn complex systems into clean ones — and leave teams stronger than I found them. 13 years building software that lasts.
Geneva, Switzerland. Currently crafting at SQLI.
Latest Articles
Why I Run a Homelab on Three Single-Board Computers
How I self-host everything from DNS to a media server on three ARM boards connected through WireGuard, and why I think every senior engineer should own their infrastructure.
What 13 Years of Web Development Taught Me About Simplicity
After building with jQuery, Angular, React, and Next.js — the most important skill I've developed is knowing when to stop adding things.
Lessons from Migrating 2 Million Assets to Cloudinary
What I learned leading a massive asset migration for an international sports federation — from quota management to automated categorization.
Why I Replaced 120 WordPress Sites With a Single Tool
How building a page builder with Grapes.js eliminated a WordPress maintenance nightmare and cut server costs by 90%.
A/B Testing Without Third-Party Scripts: Lambda@Edge and Client Fingerprinting
How I built a consistent, privacy-respecting A/B testing system using client fingerprinting and random seeds at the edge — no cookies, no third-party scripts.
Building a Real-Time BPM Analyzer That Runs Entirely in the Browser
The story behind an open-source library that detects music tempo client-side using the Web Audio API — and why I'm now training a neural network to do it better.
About
I've been building for the web since 2013 — from jQuery and PHP to React, Next.js, and cloud-native architectures. Along the way, I've led cross-functional teams, owned product roadmaps, and shipped platforms across luxury, sports, media, and e-commerce industries. What stayed constant is a focus on systems that teams can maintain long after I've moved on.
I maintain an open-source audio analysis library, teach programming privately, and run self-hosted infrastructure on single-board computers. I write about what I build — because the best way to deepen expertise is to explain it.
Let's talk
Got a hard problem, an ambitious project, or a team that needs a senior pair of hands? I'd love to hear about it.
d.lepaux@gmail.com