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Hi there, I'm Lenny Garnier, a full-stack software engineer specializing in TypeScript, Nest.js, and React. I design secure, scalable data systems and AI-driven features, always aiming for high-quality, maintainable code and robust technical solutions in demanding data environments. I enjoy bridging frontend and backend work to ship reliable features quickly, collaborating across teams to turn complex requirements into intuitive, performant applications.…Hi there, I'm Lenny Garnier, a full-stack software engineer specializing in TypeScript, Nest.js, and React. I design secure, scalable data systems and AI-driven features, always aiming for high-quality, maintainable code and robust technical solutions in demanding data environments. I enjoy bridging frontend and backend work to ship reliable features quickly, collaborating across teams to turn complex requirements into intuitive, performant applications.

Lenny Garnier

Full Stack Developer, Back-End Developer, Front-End Developer, +3

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Hi there, I'm Lenny Garnier, a full-stack software engineer specializing in TypeScript, Nest.js, and React. I design secure, scalable data systems and AI-driven features, always aiming for high-quality, maintainable code and robust technical solutions in demanding data environments. I enjoy bridging frontend and backend work to ship reliable features quickly, collaborating across teams to turn complex requirements into intuitive, performant applications.…Hi there, I'm Lenny Garnier, a full-stack software engineer specializing in TypeScript, Nest.js, and React. I design secure, scalable data systems and AI-driven features, always aiming for high-quality, maintainable code and robust technical solutions in demanding data environments. I enjoy bridging frontend and backend work to ship reliable features quickly, collaborating across teams to turn complex requirements into intuitive, performant applications.

Available to hire

Hi there, I’m Lenny Garnier, a full-stack software engineer specializing in TypeScript, Nest.js, and React. I design secure, scalable data systems and AI-driven features, always aiming for high-quality, maintainable code and robust technical solutions in demanding data environments.

I enjoy bridging frontend and backend work to ship reliable features quickly, collaborating across teams to turn complex requirements into intuitive, performant applications.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Language

English

Advanced

Work Experience

Full-Stack Engineer at Polycea (Ex Polyconseil)

May 1, 2025 - January 1, 2026

Architected a centralized data synchronization system (RCU) using Hexagonal Architecture for real-time consistency across high-traffic applications. Developed a secure Vault module for gold trading integrating the Skaleet Core Banking Platform with SSR for sensitive data grids. Built an abstract, headless Table component with TanStack Table, reducing boilerplate and accelerating feature delivery by 30%. Refactored authentication flows and data integrity checks, reducing system errors by 30%. Tech stack: NestJS, React, TypeScript, PostgreSQL, JWT.

Software Engineer Intern at Racemappr

January 1, 2024 - January 1, 2025

Streamlined development processes and code reviews to increase sprint velocity by 15%. Built an AI-assisted calendar component with an AI-suggested goal-setting feature to boost user engagement. Implemented unified JWT authentication across web and mobile platforms using Supabase and Prisma. Delivered scalable frontend and backend features for a public application serving a broad user base.

Mobile Engineer Intern at Feelbat

January 1, 2023 - December 1, 2023

Improved application loading time by 40% compared to the initial MVP. Led architecture redesign from MVP to a scalable system to support future feature growth. Developed Bluetooth pairing functionality between the mobile app and Feelbat crack sensors. Headed the frontend development of the mobile app, ensuring component reusability and stability.

Pedagogical Assistant at Epitech

January 1, 2022 - January 1, 2023

Led technical workshops and talks on emerging technologies, improving student project completion rates by 15%. Mentored students through complex programming projects, focusing on best practices, debugging, and software architecture.