Vivien Gontier
Software engineer - Rouen, France
I build products that work and keep working. I'm a software engineer at Lemonway, a French payments company, where I work on the merchant back office and PaygreenJS, our public payment library.
I like figuring out what the real problem is before writing code, and I care about shipping things that don't break.
Selected work
All projects →- Sumi iOS app for learning to read and write Japanese kana and JLPT N5 kanji. Adaptive quiz, handwriting feedback, full offline mode. No account, no ads, free.
- Arche Self-hosted CLI that wires a Jira ticket to a GitLab merge request via a plan → execute → review pipeline with human approval gates. Code runs in per-run Docker sandboxes; LLM calls go through OpenRouter.
- Spec2Code 48h hackathon prototype (team of 3) chaining Jira + GitLab + OpenAI: a prompt becomes a Jira ticket, then a generated branch, then an MR auto-reviewed by another LLM pass.
- Paygreen Back Office Dashboard for merchants managing their online payments and stores
Blog
All posts →Experience
Résumé (PDF) ↗- 2024 -
- Lemonway Software engineer - Payments
- 2023
- We Invest Back-end software engineer - PropTech, Brussels
- 2019 - 21
- Freelance Full-stack developer