What I've built.

Live product

Klyrio

Reservations, calendar and seasons, invoices and payments, several properties — a product I specified, built, shipped and still run today.

Live demo → Web site →

A chess application built step by step, running in the browser

Case study · AI SDD · 4 episodes

A chess game from scratch, with AI SDD

A real chess application built from an empty repository with the AI SDD method: each feature specified with its tests, implemented by AI, then reviewed and integrated by a human. TypeScript, Rust and Stockfish, one episode per feature.

Read the series →

Legacy modernization

Rebuild legacy

Eight steps to move a C++, PL/SQL, Visual Basic, Delphi, WinDev or COBOL application to Java, Go or Rust with React: the knowledge recovered first, today's behaviour pinned by tests, then a migration phase by phase.

See the 8 steps →

Open source · IoT

AVA Home

A connected-home platform: sensors reporting over MQTT, event history in PostgreSQL, and heating regulation driving the radiators — observe, store, control.

See it on GitHub →

Open source · Rust

Doka

An encrypted document management system written by hand in Rust since 2022: document, file, session, key and admin microservices on PostgreSQL, ChaCha20 encryption and a CLI.

See it on GitHub →

Open to senior fullstack roles · fully remote from France

Denis Crespe — senior fullstack developer.

Java and Spring Boot on the server. Vue 3 and TypeScript in the browser. I take a business feature from the API contract to the screen — on systems that are not allowed to break.

Discuss a role See my track record

Server: Java 17–21 (since 1.4) · Spring Boot · Spring Cloud · Hibernate · REST / OpenAPI 3.0 · SOAP / Axis · Microservices · Hexagonal architecture · JMS / ActiveMQ · IBM MQ Series · ESB · JBoss · WebSphere
Front: Vue 3 · TypeScript · JavaScript
Data: Oracle · PL/SQL and its tuning · Pro*C · PostgreSQL · MariaDB · Informix · Ehcache
Native: Rust · C / C++ · Visual C++ · DCOM
Delivery: Docker · Kubernetes · Rancher · AWS · Git · Jenkins · Maven · Cargo · Sonar · Bash · Linux · Solaris · Windows
Method: Spec-driven development · AI-assisted engineering · UML

Finance

Private banking, asset management and fund administration — KBL, CACEIS, SGAM, CNCE, ABC Arbitrage.

Aviation & insurance

Aircraft charter operations at GlobalJet; life-insurance platform work at Silverlake in Canada.

Public sector

UGAP.fr procurement, the Luxembourg Chamber of Deputies, and the BC Ministry of Forests.

Senior fullstack roles · fully remote from France · European teams · working in English and French

Send me the role.

Paste the job spec, or a link to the posting. I read it myself and reply personally — including when it is not a fit, and why.