Thomas Rossier

Chief Technology Officer | AI & Engineering at Scale

About me

An ISEN-trained engineer, I started out as a developer at Thales, in a defence environment where rigour and quality are non-negotiable.

At EGERIE, a cybersecurity software publisher, I grew from first developer to CTO through more than €40M of funding (Series A & B): 7 squads, 50 people, a product certified by ANSSI and recognised by Gartner. My first real experience of transformation at scale, both technical and human.

At leboncoin, as Senior Engineering Manager, I led high-traffic transactional platforms and supported the teams through the company’s international expansion. As a member of the internal AI committee, I helped turn LLMs, RAG and agents into a genuine team capability.

Today, as CTO of Oodrive Sign, a sovereign electronic signature solution, I lead Engineering — 20 engineers across France and Tunisia. My focus: architecture, observability, PKI / eIDAS, FinOps, and industrialising AI across the whole development lifecycle.

The common thread: a transformation only works if the teams carry it with you.

Experience

  1. Oodrive

    Chief Technology Officer - January 2026 – Present

    • Head of Engineering for the Oodrive Sign division, a sovereign electronic signature solution: 20 engineers in France and Tunisia.
    • Executive committee member: product, technology, organisation, delivery and Engineering roadmap decisions.
    • Industrialising AI in Engineering: agentics, LLM agents, skills, RAG, MCP, n8n, AI labs and AI-augmented SDLC workflows.
    • Technical governance: RFCs, ADRs, architecture reviews, Engineering standards, technical debt and target architecture.
    • SDLC leadership: delivery, quality, predictability, DORA metrics, continuous improvement and Engineering practices.
    • Production observability, reliability and resilience: Grafana, monitoring, alerting, incidents, SLOs/KPIs, circuit breakers, fallbacks and event-driven architecture.
    • Platform modernisation: Docker, Kubernetes, CI/CD, environments, deployments and production hardening.
    • FinOps: AWS & Outscale infrastructure optimisation, cost tracking, ROI, build-vs-buy decisions and production cost control.
    • Nearshore organisation: 40% of the tech workforce, France/Tunisia alignment, delivery quality and team autonomy.
    • Technical and organisational change management: AI adoption, new Engineering practices, Tech Lead coaching and upskilling.

    Tech stack : Java, Angular, JavaScript, REST API, Docker, Kubernetes, CI/CD, Grafana, PKI, eIDAS v2-v3, Certificate Authority, Cybersecurity, GenAI, LLM, RAG, MCP, n8n, Observability, DevOps, SRE, FinOps

  2. leboncoin

    Senior Engineering Manager · Hands On - January 2022 – January 2026 . 4 years 1 month

    • Managed and supported several feature teams in an Agile organisation (SAFe, SoS, Spotify model).
    • Worked on high-traffic transactional platforms: booking, payments, scalability, reliability, resilience and event-driven architecture.
    • Member of the internal AI committee: framing LLM and RAG use cases, code review agents, n8n automations and AI-augmented Engineering workflows.
    • Aligned Engineering goals with Product, Business and Programme priorities.
    • Drove team performance: delivery, quality, predictability, DORA metrics and continuous improvement.
    • Worked closely with Product Managers, Product Owners, Architects, Tech Leads, Data, UX/UI and QA teams.
    • Contributed to architecture decisions (RFCs, ADRs) and technical governance: Engineering standards, technical debt, software quality and observability.
    • Ran technical steering committees to track risks, trade-offs, dependencies and business / technical priorities.
    • Helped teams adopt AI practices: specifications, code reviews, testing, technical documentation and automation.
    • Hiring, coaching and talent development: upskilling, career plans, training and HR support.

    Tech stack : ReactJS, Next.js, Go, AWS, AWS Neptune, Kotlin, SwiftUI, ML, GenAI, Datadog, Kafka, Gerrit, Firebase, ScyllaDB, Redis Graph, Neo4j, Scrum, SAFe, LeSS

  3. EGERIE Software

    French Tech member · ANSSI certified · Gartner Magic Quadrant & Vendor to Watch

    5 years 8 months

    Chief Technology Officer - July 2018 – January 2022 . 3 years 7 months

    • Technical leadership, hiring and management of the engineering teams following several funding rounds totalling over €40M (Series A & B). Built 7 cross-functional squads of 50 people: Engineering Manager, PO, PE, Tech Lead, developers, Release Manager, QA, CS, DevOps.
    • Advised by French unicorns, including PayFit, and Next40 companies.
    • Created an incubator, Campus EGERIE, to accelerate hiring.
    • Career follow-up and development for team members.
    • Workshops with the executive committee (CODIR) and the operations committee (COMOP).
    • Owner of development quality and training: design patterns, PSR, DevOps, secure development and technology watch.
    • Security: code obfuscation with Zend Guard Loader, symmetric and asymmetric encryption, TOTP 2FA, PHP compilation with HHVM, YesWeHack bug bounties, OWASP, audits and pentests.
    • Project tracking and ways of working: flat management, Lean, Scrum, Agile and process gamification.
    • R&D and software development with Symfony 5 / API Platform / ReactJS 16.
    • Member of the Social and Economic Committee (CSE).

    Software Engineer & Scrum Master - June 2016 – July 2018 . 2 years 2 months

    • Developed a cyber risk management software: Silex / Symfony / ReactJS, REST APIs with API Platform.
    • Migrated the platform from Silex 2 / Symfony 2 to Symfony 5.
    • Performance improvements with Blackfire: APCu cache, PSR-6 & PSR-16, HTTP cache, MySQL tuning, Doctrine Native Query, OPcache, PHP-FPM, PHP 7 vs HHVM.
    • Ongoing maintenance and evolution of an ANSSI-certified product.
    • Introduced good practices: code review, peer review, pair programming, PSR coding styles and guidelines.
    • End-to-end tests with TDD and Panther, smoke and sanity tests with Behat and PHPUnit.
    • Automated deployment pipelines with GitLab CI.
    • Scrum Master, introduced the Agile Scrum framework.

    Tech stack : Cybersecurity, Symfony 2/5, Silex 1/2, ReactJS 14/16, VueJS 3, API Platform, Formik, MUI, GitLab CI, Docker, Ansible, Node.js, JMeter, Blackfire, TDD, Panther, SonarQube, PHPUnit, MariaDB, APCu, Rector, PHPStan, ESLint

  4. Fidens

    Software Engineer - June 2012 – June 2016 . 4 years 1 month

    • Built and led a team of 5 developers.
    • Developed a threat analysis software.
    • Migrated a native PHP project to Silex 2 / Symfony 2 in 5 months.
    • Ongoing maintenance and evolution of the software.
    • Introduced good practices: code review, peer review, PSR coding styles and guidelines.
    • Smoke and sanity tests with Selenium and PHPUnit.
    • Automated deployments and tests with TeamCity CI.

    Tech stack : Cybersecurity, Symfony 2, Silex 2, ReactJS, REST API, Git, TeamCity, Elasticsearch, TDD, Selenium, MySQL, Behat, PHPUnit, SonarQube, Highcharts, Less, IceScrum, Blackfire

  5. Thales

    Software Engineer - January 2010 – May 2012 . 2 years 5 months

    • Developed internal tools in PHP & JS for defence and key-account projects.
    • Functional and technical design: UML, Merise, data models and user journeys.
    • First experience in a defence environment, with a strong focus on quality, traceability and reliability of deliverables.
    • Gathered and formalised requirements with internal users and project stakeholders.
    • Designed and structured MySQL databases for business needs and reporting.
    • Front-end and back-end development with Zend Framework, jQuery, AJAX, Bootstrap and Twig, with responsive design.
    • Deliverable tracking and project reporting: planning, workload, costs, deadlines, milestones and risks.

    Tech stack : MS Project, Excel, Zend Framework, jQuery, AJAX, Bootstrap, Twig, UML, Merise, Security, Defence

  6. Concept Multiservice

    Symfony 4 / ReactJS 14 Developer – Freelance - January 2020 – March 2020 . 3 months

    • Designed a platform for renovation projects.
    • Front-end development with ReactJS / Formik / Yup.
    • Property management back office in Symfony 4 (EasyAdmin bundle, LiipImagine image cache).
    • Smoke tests with Panther.
    • Deployment with Ansible.

    Tech stack : Symfony 4, ReactJS 14, React Router, Formik, Yup, EasyAdmin, LiipImagine, Panther, PHPUnit

  7. Sokoa Enterprise

    PHP Zend Framework Developer – Freelance - September 2011 – May 2012 . 9 months

    • Developed a customer invoice management tool.
    • Back-end / front-end PHP development with Zend Framework.
    • Dynamic user interfaces with jQuery.
    • Wrote the specifications and managed the project with the client.
    • Functional and unit tests with PHPUnit: WebTestCase, TestCase.
    • Technology watch: code obfuscation with Zend Guard Loader, Zend Framework, PHP 5.6, OOP, jQuery, MariaDB.

    Tech stack : Zend Framework, jQuery, Bootstrap, OOP, Zend Guard Loader, MongoDB, PHPUnit

Personal projects

  1. Symfony 4 / ReactJS 14 Developer - March 2020 – September 2020 . 7 months

    • Built a SPA (Single Page Application) with Symfony 4 / API Platform / ReactJS 14.
    • Built a back office to manage articles and posts.
    • Built a back office to manage a résumé: experience, education, hobbies, etc.
    • Deployed a LAMP stack with Docker.

    Tech stack : Symfony 4, ReactJS, API Platform, JWT, MariaDB, Symfony PSR-6 file cache, Axios, Doctrine ORM

  2. Full-Stack JavaScript Developer - February 2016 – November 2016 . 10 months

    • Built a humorous classified ads website with ExpressJS.
    • Design, documentation and modelling.
    • Front-end and back-end development entirely in JavaScript and VueJS 2.
    • Technology watch and competitive benchmark: NodeJS, AngularJS, RequireJS, Bookshelf ORM, ExpressJS, TypeORM.

    Tech stack : NodeJS, VueJS, AngularJS, ExpressJS, Bookshelf ORM, RequireJS, Jest, Docker

Skills

  • PHP
  • Symfony
  • Bootstrap
  • Zend Framework
  • API Platform
  • Silex
  • Jira
  • JavaScript
  • React
  • Vue.js
  • Redux
  • Angular
  • Material UI
  • jQuery
  • Docker
  • Kubernetes
  • Terraform
  • Argo CD
  • Longhorn
  • Crossplane
  • Grafana
  • Node.js
  • Ansible
  • Vagrant
  • Git
  • npm
  • Slack
  • TeamCity
  • CircleCI
  • Panther
  • PHPUnit
  • Bookshelf.js
  • Microsoft Teams
  • Amazon Neptune
  • AWS
  • Elasticsearch
  • Next.js
  • Firebase
  • Datadog
  • ScyllaDB

Hobbies

Hobbies : Travel, Skiing, Cycling, Cinema, Volleyball, Badminton