Looking for a job

Vincent Groslier

@vincentgroslier

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I build privacy-first full-stack products and rescue critical legacy systems.

Japan

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What I'm looking for

I'm looking to build user-centered products where I can combine full-stack engineering, scalable architecture, privacy-conscious design, and hands-on problem-solving across frontend and backend systems.

I'm building MoiMoiMoi at OxyMammoth, a privacy-first introspection application with AI-guided analysis, secure journaling, and end-to-end encryption. I architected its monorepo foundation, integrated Rive-driven interactive visuals, and designed a zero-knowledge approach for privacy-conscious AI experiences.

At Biotech Dental Digital, I rewrote critical manufacturing and financial systems, replacing rigid legacy logic with scalable C#/.NET and database-driven architecture. My work enabled label generation in 10 languages, moved financial calculations out of the client, and turned opaque Excel workflows into actionable dashboards.

I also investigated production issues others had accepted as routine: I reduced shipping validation freezes from 15 minutes to 2 minutes, stopped daily server crashes, lowered peak server load from 100% to 40% through MongoDB indexing, and eliminated 60+ daily blocking errors by fixing scanner input handling at the source.

Earlier at Potluck, I worked autonomously as the sole engineer in Japan, improving a React Native Android app and building restaurant SaaS interfaces across web and tablet. I enjoy product engineering that connects reliable backend logic, clear user experiences, and practical problem-solving.

Experience

Work history, roles, and key accomplishments

Current

Founder & Lead Product Engineer

Current

OxyMammoth

Nov 2025 - Present (9 months)

Built MoiMoiMoi, a privacy-first introspection SaaS featuring an AI guide persona. Implemented end-to-end encryption (E2EE) and a Zero-Knowledge architecture to protect sensitive user data. Integrated custom interactive animations using Rive and engineered a scalable monorepo structure for future web applications.

TypeScript React Next.js MongoDB NodeJS Tailwind

Full-Stack Developer

Biotech Dental Digital

Oct 2023 - Nov 2025 (2 years 1 month)

Re-architected critical legacy manufacturing and printing engines into dynamic C# systems supporting 10 languages. Tuned MongoDB indexing, reducing server CPU from 100% to 40%. Fixed critical data-corruption bugs and eliminated printing freezes (-85% wait time). Built secure financial modules, eliminating calculation errors and replacing opaque spreadsheet tracking.

C#.NET JavaScript NodeJS Express MongoDB Database Optimization

React / React Native Developer

Potluck (Rym&CO)

May 2021 - Jul 2022 (1 year 2 months)

Sole engineer in Tokyo building restaurant SaaS platforms (Client Web, Waiter Tablet, Admin Dashboard). Implemented ~90% of the core React frontend autonomously and resolved complex hardware integration blockers with Epson receipt printers by debugging low-level C libraries.

React React Native TypeScript JavaScript Mobile Development Hardware Integration

Teaching Assistant

Code Chrysalis

Oct 2020 - Dec 2020 (2 months)

Mentored coding bootcamp students through full-stack JavaScript and Node.js software projects. Conducted technical code reviews, assisted with real-time debugging, and led interactive workshops on Git workflows and frontend fundamentals.

JavaScript NodeJS Git Code Review Mentorship