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Senior backend engineer with 10 years of experience designing, building and operaWng high-throughput distributed systems in JAVA, Node.js with strong AWS cloud skills (AWS CerWfied Developer, Kubernetes). Track record spans large-scale internal pla_orms at Amazon LogisWcs to a healthcare microservices pla_orm for France's naWonal rare disease registry. Comfortable owning a system end-to-end: architecture, implementaWon, infrastructure-as-code, and observability.…Senior backend engineer with 10 years of experience designing, building and operaWng high-throughput distributed systems in JAVA, Node.js with strong AWS cloud skills (AWS CerWfied Developer, Kubernetes). Track record spans large-scale internal pla_orms at Amazon LogisWcs to a healthcare microservices pla_orm for France's naWonal rare disease registry. Comfortable owning a system end-to-end: architecture, implementaWon, infrastructure-as-code, and observability.

MATTHIEU LEROY

Back-End Developer, Full Stack Developer, Web Developer, +2

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Senior backend engineer with 10 years of experience designing, building and operaWng high-throughput distributed systems in JAVA, Node.js with strong AWS cloud skills (AWS CerWfied Developer, Kubernetes). Track record spans large-scale internal pla_orms at Amazon LogisWcs to a healthcare microservices pla_orm for France's naWonal rare disease registry. Comfortable owning a system end-to-end: architecture, implementaWon, infrastructure-as-code, and observability.…Senior backend engineer with 10 years of experience designing, building and operaWng high-throughput distributed systems in JAVA, Node.js with strong AWS cloud skills (AWS CerWfied Developer, Kubernetes). Track record spans large-scale internal pla_orms at Amazon LogisWcs to a healthcare microservices pla_orm for France's naWonal rare disease registry. Comfortable owning a system end-to-end: architecture, implementaWon, infrastructure-as-code, and observability.

Available to hire

Senior backend engineer with 10 years of experience designing, building and operaWng high-throughput distributed systems
in JAVA, Node.js with strong AWS cloud skills (AWS CerWfied Developer, Kubernetes). Track record spans large-scale internal
pla_orms at Amazon LogisWcs to a healthcare microservices pla_orm for France’s naWonal rare disease registry. Comfortable
owning a system end-to-end: architecture, implementaWon, infrastructure-as-code, and observability.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

French

Fluent

English

Advanced

Work Experience

Senior Fullstack Engineer at BNDMR — AP-HP Paris

January 1, 2026 - Present

Backend engineer on France’s national rare disease registry healthcare platform affiliated with AP-HP, within HDS compliance requirements. Worked across a Maven monorepo of 20+ modules powering 5 microservices, built on Grizzly, Jersey, and Guice, backed by PostgreSQL deployed on a Kubernetes cluster. Achieved a 10x performance gain on critical endpoints by offloading reads to a PostgreSQL read replica, parallelizing SQL requests, and bypassing Hibernate in favor of raw JDBC to reduce overhead. Built observability with Micrometer, Prometheus, and Grafana (HikariCP/JVM/HTTP dashboards and alerts for critical tasks).

Senior Fullstack Engineer at Amazon Paris

May 1, 2021 - September 1, 2025

Owned internal applications end-to-end (architecture, implementation, and infrastructure) across frontend, backend, and AWS. Shipped two capacity-management tools covering 10+ billion packages per year across 500 US and 450 European stations, planning from next-day (J+1/2/3) to 17 weeks out, serving 10,000+ internal users under strict availability requirements at large data scale. Developed backend services in Java and Node.js leveraging AWS Lambda and containerized ECS tasks. Led operational improvement via bi-weekly post-on-call reviews for an 11-developer team based on incidents and user feedback. Owned infrastructure using AWS and CDK (CI/CD, monitoring) and built frontends in React and TypeScript.

Backend Node.js Engineer at Ekino Paris

August 1, 2018 - April 1, 2021

Developed the primary API for Groupe Canal+ serving web, mobile, and set-top-box front ends, supporting traffic peaks up to 800,000 concurrent users within a 6-developer Agile team. Contributed new features and built unit/integration test suites to reach 95% coverage, strengthening API resilience. Stack included GraphQL, TypeScript, Node.js, Express, and AWS.

Backend Engineer at Omnilog Paris

August 1, 2016 - July 1, 2018

Consultant for France Télévisions and L'Équipe. Contributed to the launch of France.tv by building backend services within a 6-developer team using Symfony, along with Node.js.