> Markdown version of [/jobs/ext/2328296-penetration-tester-mid-senior](https://www.wearedevelopers.com/jobs/ext/2328296-penetration-tester-mid-senior). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Penetration Tester (Mid+/ Senior)

- **Company:** UnderDefense
- **Location:** France (Remote available)
- **Experience:** Experienced
- **Contract:** Permanent contract
- **Skills:** .NET Framework, Microsoft Windows, Active Directory, Artificial Intelligence, Apple IOS, Apple Mac Systems, Software System Penetration Testing, C++ (Programming Language), Cloud Computing, Linux, Python (Programming Language), Red Team (Cyber Security), Vulnerability Analysis
- **Published:** August 12, 2026
- **Apply:** https://fr.indeed.com/viewjob?jk=9703aeb67bc8d4b7

## About the Role

We are looking for bright and self-motivated individuals to join our technical team. Someone who is passionate about Security as we are., * Red Team (core): hands-on experience with C2 frameworks; base in exploit development and writing implants/beacons for C2.

 * Deep Internal / Active Directory penetration testing.
 * OPSEC techniques and understanding of how SOC and defensive mechanisms work - and how to evade them.
 * Mobile, Desktop, IoT (willing to cover): general testing techniques; understanding of Windows/Linux/MacOS/iOS/Android internals and system-level vulnerabilities; for IoT - protocols plus basic hardware skills (disassemble a board, solder).
 * Cloud: understanding of cloud infrastructure, privileges and related attack vectors.
 * Business-logic vulnerabilities: proven experience and breadth in finding non-standard logic flaws.
 * Deep adoption of AI tooling (own setups, MCP; AI integrated into the workflow - not surface-level use).
 * English sufficient to independently present a report to the client and answer questions.
 * Web is not the core focus but assumed by default at this level.

Preferred Experience: OSCP / CRTO / OSEP or other related offensive-security certifications; ability to code in Python, C/C++, .NET or similar.

## Description

* Independently own and deliver Red Team engagements end-to-end (planning, execution, reporting, client delivery).
 * Take on complex projects across Mobile, Desktop and IoT
 * Develop custom implants, beacons and exploits for Windows/Mac when engagements require it.
 * Create detailed reports explaining technical and logical findings, business risk and prioritized recommendations.
 * Share expertise: run lessons-learned, internal lectures and knowledge sharing
 * Act as a role model by example - take the initiative, dig in, take ownership.
 * Collaborate closely with the team and contribute to continuous improvement of teampentest capabilities.
 * Think outside the box and simulate real adversarial approaches.

What we offer:

 * Growth, really fast growth
 * Good salary + really challengeable projects
 * Brilliant Team
 * Flexible working hours
 * Paid vacation and sick-leaves
 * Internal training and workshop (conferences, workshops, training, etc.)
 * English courses
 * Work-rest balance support ( foosball, workout station)


## Related Videos

- [Docker network without Docker](https://www.wearedevelopers.com/videos/1418-docker-network-without-docker)
- [Xcode development redefAIned](https://www.wearedevelopers.com/videos/100195-xcode-development-redefained)
- [This Is Not Your Father's .NET](https://www.wearedevelopers.com/videos/967-this-is-not-your-father-s-net)
- [Security Pitfalls for Software Engineers](https://www.wearedevelopers.com/videos/726-security-pitfalls-for-software-engineers)
- [Discover the open source trio you didn’t expect: .NET and PostgreSQL on Linux](https://www.wearedevelopers.com/videos/2042-discover-the-open-source-trio-you-didn-t-expect-net-and-postgresql-on-linux)
- [Docker exec without Docker](https://www.wearedevelopers.com/videos/1094-docker-exec-without-docker)

## Related Articles

- [9 Ways to Make Money Hacking](https://www.wearedevelopers.com/magazine/333-9-ways-to-make-money-hacking)
- [Dev Digest 134 - Where pixels sing?](https://www.wearedevelopers.com/magazine/477-dev-digest-134-where-pixels-sing)
- [Dev Digest 191: Malware interviews, EU ❤️ Open Source and Skilled Agents](https://www.wearedevelopers.com/magazine/645-dev-digest-191-malware-interviews-eu-open-source-and-skilled-agents)
- [The 8 Best Code Testing Tools](https://www.wearedevelopers.com/magazine/402-the-8-best-code-testing-tools)
- [Dev Digest 121 - AI goes offline](https://www.wearedevelopers.com/magazine/456-dev-digest-121-ai-goes-offline)
- [Events like RSAC Get You CISOs. Developers Decide What Actually Gets Deployed.](https://www.wearedevelopers.com/magazine/693-events-like-rsac-get-you-cisos-developers-decide-what-actually-gets-deployed)