Guillaume Castagnino

Profile

Engineer graduated from IIE.
I have built my entire career in software development, including over a decade dedicated to cybersecurity — moving from hands-on engineering to product management, and from legacy infrastructures to cloud-native ecosystems. This dual technical-and-product perspective lets me bridge engineering teams, customers, and business goals.
I am now looking for a Product Owner role focused on technical and cybersecurity challenges that deliver real value to customers.

Experience

VulnIT — DenyAll — Rohde-Schwarz Cybersecurity — UBIKA

Paris area, FR

Through mergers and acquisitions, this single employer became 4 different companies over time.
VulnIT was a small company providing a vulnerability scanner and assessment tool. It was acquired by DenyAll, a Web Application Firewall vendor, to complete its portfolio — after which DenyAll went through 2 changes of ownership.

Product Manager for “Cloud Protector” @ UBIKA

March 2022 – present

  • Owning the product strategy and roadmap for “Cloud Protector”, the SaaS flavor of the Web Application Firewall
  • Managing relationships with “Cloud Protector” infrastructure and service providers
  • Co-leading, with the CTO, the full reboot of “Cloud Protector” using a Lean approach and strengthening portfolio synergy
  • Defining the launch plan and sales model for the new security modules of the reboot
  • Preparing and presenting webinars to prospects and customers
  • Presenting the roadmap at company summits and running workshops with customer working groups
  • Conducting one-to-one roadmap reviews with customers to gather feedback and prioritize
  • Studying commercial partnership opportunities alongside the head of Product Management
  • PO
  • PM
  • Kanban
  • Lean
  • Jira
  • Confluence

Product Owner for “Cloud Protector” @ RSCS

Jan 2018 – March 2022

  • Managing “Cloud Protector”, the SaaS flavor of the Web Application Firewall, alongside the head of Product Management
  • Reducing the COGS of “Cloud Protector”, including a full platform migration
  • Designing the MVP of a new product targeted at DevSecOps teams
  • Acting as backup Ops on duty to ensure “Cloud Protector” availability
  • PO
  • Scrum
  • Jira
  • Confluence

Senior Software Engineer @ DenyAll – RSCS

Jul 2012 – Jan 2018

  • Acting as Product Owner for “Vulnerability Manager”
  • Building the SaaS platform for the Vulnerability Scanner (high availability, load balancing, database redundancy…)
  • Developing and maintaining “Vulnerability Manager”, notably reworking the website crawler to handle the growing use of async requests (SPA)
  • Developing, refactoring and maintaining the core of the Web Application Firewall
  • Developing and maintaining “Cloud Protector”, the SaaS version of the Web Application Firewall
  • Organizing and facilitating the Scrum process
  • PO
  • Scrum
  • vCloud
  • C
  • Java
  • PHP
  • Python
  • Ansible
  • PostgreSQL
  • Vulnerability assessment
  • Network

Senior Software Engineer @ VulnIT

Feb 2011 – Jul 2012

  • VulnIT provided “Vulnerability Manager”, a vulnerability scanner historically shipped as a bootable USB key
  • Redesigning the product architecture: moving from a Java/Swing monolith to an n-tier architecture with a web UI
  • Delivering the product as a Virtual Machine image with a fully automated image build in CI
  • Designing “agents” deployable across segmented networks and connected to a central Vulnerability Manager
  • Virtualization
  • Network
  • Vulnerability assessment
  • Java
  • PHP
  • PostgreSQL

PepperWay SCOP ARL

Paris, FR

PepperWay was a web agency I co-founded with former Telecom Italia colleagues.

Co-founder, CTO

Oct 2009 – Feb 2011

  • Building the web hosting cluster with state-of-the-art high availability (heartbeat, HAProxy, nginx, DRBD, database redundancy)
  • Building the mail hosting cluster (Postfix, Cyrus IMAP) with modern antispam technologies (DKIM, SPF) and HA storage replication (DRBD)
  • Acting as technical lead on customer projects, from e-commerce portal integration and customization (PrestaShop) to fully custom-built websites
  • HA
  • Hosting
  • AntiSpam
  • PHP
  • PostgreSQL

Telecom Italia France “Alice” — Free SAS

Paris, FR

Telecom Italia France was an Internet provider (“Alice”) that was bought by Free. No employer change.

Software Engineer @ Free SAS

Aug 2008 – Oct 2009

  • Migrating the Information System, with Perl/MySQL developments
  • Fully redesigning the B2C “Alice” customer portal (migration from PHP to Perl)
  • Redesigning the “Alice” customer subscription flow, from administrative account creation to modem and line delivery
  • PHP
  • Perl
  • HTML
  • CSS
  • MySQL

Software Engineer @ TIF “Alice”

Jul 2006 – Aug 2008

  • Maintaining, evolving and refactoring the subscription interface and customer portal in close collaboration with the B2C sales team
  • Integrating the w-HA online micro-payment service
  • Designing SOAP interfaces for Information System interconnections
  • Managing the B2C financial recovery flow
  • Managing production deliveries
  • Working with Agile practices (XP, pair programming)
  • PHP
  • Perl
  • HTML
  • CSS
  • MySQL
  • SOAP

IDEALX

Paris, FR

Software Engineer

Aug 2005 – Jul 2006

  • Packaging “IDX::PKI” for publishing
  • 8-month mission for Telecom Italia France, Signup/Selfcare team: B2C customer portal maintenance, SOAP web services design and development, and w-HA payment interface
  • Perl
  • PHP
  • SOAP

Education

IIE-CNAM/ENSIIE engineering diploma (Master’s degree)

Sep 2002 - June 2005

Specialised in advanced information systems and databases, networks and security, formal programming, robotics and virtual reality.
Guillaume Castagnino
  • +33 6 73 85 46 69
  • guillaume@castagnino.org
  • cv.castagnino.org
  • 21 rue Roger Henry
    78210 Saint-Cyr-l’École
    France
  • DoB: April 14, 1982

Skills

    • Soft skills
    • Analytical mindset
    • Active listening
    • Cross-team collaboration
      Product Management
    • Agile methodologies (Scrum, Kanban)
    • Lean product development
    • Value optimization
    • Roadmapping & prioritization
    • Jira & Confluence
      Technical
    • Strong programming and sysadmin background (Linux)
    • Cybersecurity (WAF, vulnerability assessment)
    • Cloud & SaaS platforms

Languages

  • French
    Native
  • English
    Professional Working Skills – TOEIC: 875

Diplomas

  • Product Focus Certified Product Manager (2021)
  • PSPO I certified (2018)
  • IIE-CNAM/ENSIIE Engineer (2005)

Interests

  • Bike
  • Photography
  • OpenStreetMap
  • System administration
  • Piano