Xavier Chevalier

SaaS application that centralizes financial income from foreign brokers (Trading212, Interactive Brokers, Trade Republic, Mintos...) and generates a step-by-step guide to fill out French tax forms (2042, 2047, 2074-CMV, 3916-BIS).

Main Responsibilities

- End-to-end product design: strategic vision, market research (TAM / SAM / SOM), competitive analysis, and user experience design.

- Full cycle management: discovery, delivery, deployment, continuous improvement.

Key Achievements

- Designed a platform based on a Domain-Driven Design architecture (DDD, Effect, TanStack Start, Drizzle ORM, PostgreSQL) adapted to French tax regulations.

- Implemented intelligent document parsing via AI to automatically extract financial transactions from broker statements.

- Developed tax calculations compliant with the French General Tax Code for various income types and forms (2042, 2047, 2074 CMV, 3916-BIS).

- Established high quality standards: strict TypeScript typing, automated testing (Vitest, Playwright), functional programming with typed error handling.

- Designed a scalable infrastructure (Railway, AWS S3, Stripe, Sentry) to support load increases during tax declaration periods.

Challenges & Impact

- Compliance and security: GDPR-oriented design and sensitive data protection, a key factor for product credibility.

- Reliable tax calculations and reduced error risk for individual investors unfamiliar with taxation.

Wise Building is a digital solution for smart office buildings 💼 and university campuses 🎓, with prestigious clients such as Eiffage, Vinci Immobilier, Smart Buildings Alliance, and RIVP (government organization).

As Lead Developer, I played a crucial role in modernizing the platform, meeting client objectives:

- Refactoring the legacy system to reduce infrastructure costs and improve development fluidity.

- High requirements for code quality and scalability, while ensuring high development velocity to meet tight deadlines.

My role involved several missions:

- Meeting project expectations by upskilling the team, particularly in TDD, DDD, and Hexagonal Architecture.

- Microservices development, serverless architecture via AWS Lambda.

- Integration of external connectors.

- Progressive migration from legacy to more modern and efficient technologies.

- Event-Driven Architecture for optimal decoupling of Bounded Contexts.

- Implementation of the Nest.js framework and CI/automated testing tools, ensuring code quality and smooth collaboration.

Skyloud is a KCSP, CKA, CKS certified company specializing in new Cloud technologies. It helps its clients, such as Air France, CNRS, and Indy, build and manage available, resilient, and scalable infrastructures.

My responsibilities included developing the monitoring and incident reporting module on Skyloud.App and acting as a referent for the team.

Context:

- Legacy, in-house architecture with files of +21,000 lines of code;

- Use of libraries deprecated for over 7 years;

- Small team of 2 developers.

✅ Support for the transition to best practices.

✅ Implementation of Clean Code and Hexagonal Architecture.

✅ Team training and application of TDD, BDD, and DDD.

✅ Implementation of a Design System with Storybook, Atomic Design approach, and visual regression testing with Chromatic.

✅ Development of a client application monitoring feature, incident reporting with summaries.