Julien Ducrot

Kboom.gg builds an interactive fantasy esports platform designed to engage fans and enhance competition through real-time experiences. Highlights: • Led the migration from multiple repositories to a unified Turborepo monorepo, improving DX, build times, and shared module management • Architected and maintained Next.js (web) and Expo (mobile) applications with a shared codebase, ensuring consistent behavior across platforms • Designed and deployed a cross-platform design system to unify visuals and component logic between web and native • Mutualized business logic, state management, and analytics across environments to reduce code duplication and improve maintainability • Integrated PostHog and Sentry for analytics, user behavior tracking, and observability, enabling data-driven iteration and reliability improvements • Oversaw performance optimization, dependency upgrades, and build tooling to ensure scalability and maintain product stability over time • Collaborated closely with designers, backend engineers, and growth teams to deliver features that drive user engagement and retention Tech stack: Next.js, React, Expo, TypeScript, Turborepo, Zustand, Sentry, PostHog, GrowthBook, Tailwind, NativeWind

Supacat is my independent product studio focused on building and launching MVPs for startups and exploring in-house digital products. The studio combines rapid prototyping, clean architecture, and strong design systems to turn early ideas into scalable applications. Highlights: • Founded and operate Supacat, delivering web and mobile experiences from concept to launch • Built uselockin.app, a personal side project centered on motivation, accountability, and habit tracking • Designed and shipped MVPs for startups and creators, covering product strategy, UX, and technical execution • Created a shared codebase for web (Next.js) and mobile (Expo) with Turborepo to accelerate iteration • Developed internal design systems, component libraries, and utilities for reuse across multiple projects • Integrated Supabase, GrowthBook, PostHog, and Sentry to support scalability, experimentation, and observability • Explored AI assisted development, applying LLM workflows for design, analytics, and code generation Tech stack: Next.js, React, React Native, Expo, TypeScript, Supabase, Turborepo, Tailwind, GrowthBook, PostHog, Sentry, OpenAI

Piana develops a fleet management platform helping companies reduce operational costs and lower their carbon footprint. Highlights: • Architected a scalable, modular frontend system to streamline vehicle and expense management workflows • Developed a cross-platform mobile app (React Native + Expo) enabling drivers to track fuel, mileage, and maintenance in real time • Partnered with design to build a shared visual system using Tokens Studio, ensuring consistency across web and mobile • Created a UI component library with full internationalization support and optimized developer ergonomics • Integrated RudderStack and Datadog for analytics and performance monitoring, supporting data-driven UX improvements Tech stack: React, React Native, Expo, TypeScript, RudderStack, Datadog, Tokens Studio

Leah is a French teleconsultation platform that has facilitated over one million consultations between healthcare professionals and patients. Highlights: • Architected a modular, scalable frontend system using a component-based architecture to support fast product growth • Developed a React Native mobile application for patients, improving accessibility and user engagement across devices • Partnered with the design team to build a unified visual identity and style guide, ensuring consistency across web and mobile • Created a cross-platform UI component library with internationalization, theming, and accessibility support • Integrated a user behavior tracking system to collect insights and continuously enhance UX based on real usage data • Implemented unit and functional testing pipelines with continuous integration to maintain stability and confidence at scale Tech stack: React, React Native, TypeScript, Design System

Oyst was a leading e-commerce platform simplifying online transactions for merchants and customers across Magento, PrestaShop, and other major ecosystems. Highlights: • Improved stability and performance across three core products — shopping tunnel, merchant dashboard, and user dashboard — through deep refactoring and architectural clean-up • Partnered with product managers to define and prioritize the product roadmap, ensuring technical feasibility aligned with business goals • Contributed to the recruitment and onboarding of new frontend engineers, helping scale the development team • Advocated for modern frontend best practices in React and Redux, improving code quality and delivery velocity Tech stack: React, Redux, TypeScript

Fashion Network is a leading digital media platform for fashion professionals, attracting over 1 million monthly visitors across 70 countries and 10 languages. Highlights: • Built a scalable, component-based frontend architecture to modernize the company’s core web platform • Partnered with designers to establish a unified visual style guide and UI component library, ensuring consistency and flexibility across international editions • Implemented internationalization (i18n) and theming support to serve multilingual audiences efficiently • Deployed a custom A/B testing framework with automated rollout capabilities to validate UX and conversion improvements • Integrated a user interaction tracking library to collect actionable insights and guide product optimization • Strengthened reliability through unit and functional testing and maintained continuous integration pipelines for seamless releases Tech stack: JavaScript, HTML, CSS, React (early adoption), jQuery, REST APIs

Attractive World is a French dating platform attracting over 2 million monthly visitors, known for its premium matchmaking experience and active member community. Highlights: • Rebuilt the main web application with a modular, component-based architecture to improve scalability and performance • Collaborated closely with designers to craft a unified visual language and responsive style guide, ensuring consistency across the product • Created a UI component library supporting internationalization (i18n), theming, and multi-platform integration • Introduced an A/B testing framework with automated deployment, enabling data-driven UX and conversion improvements • Implemented a user behavior tracking system to measure engagement and guide continuous optimization • Strengthened code quality through unit and functional testing and maintained continuous integration pipelines Tech stack: JavaScript, HTML, CSS, jQuery, REST APIs

UNIFY Digital Factory is a digital marketing company specializing in performance-based campaigns and analytics across multiple online channels. Highlights: • Refactored the JavaScript tracking engine, improving performance by 300% and significantly reducing load times for client campaigns • Optimized and rebuilt internal analytics dashboards to handle millions of events efficiently and improve data visualization speed • Redesigned dashboard UI and UX for better usability and faster insights across marketing teams • Implemented unit and functional testing pipelines, ensuring stability and reliable continuous integration • Mentored an apprentice developer, supporting their technical growth and contributing to team knowledge sharing Tech stack: JavaScript, HTML, CSS, jQuery, REST APIs