Key Facts

Remote From:

France

Full time

English

Hard Skills

Other Skills

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Communication
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Virtual Collaboration
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Teamwork
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Curiosity

Roles & Responsibilities

5+ years of experience in Java (or C/C++ with a focus on internals/compilation)
Solid understanding of Java bytecode, JVM internals, and performance implications
Experience with bytecode manipulation libraries (ASM, BCEL, etc.)
Strong software engineering practices (design, tests, code reviews)

Requirements:

Work on our Java protection product (obfuscation, anti-tamper, etc.)
Write and maintain bytecode transformations with performance and stealth in mind
Write and maintain protection against dynamic instrumentation and tampering
Ensure compatibility with a range of Java runtimes and Android versions

Quarkslab

Computer Hardware & Networking

About Quarkslab

Every cybersecurity issue is different, every solution must be. Quarkslab helps companies endow their systems and programs with customized security within the source or binary code. In order to protect the assets and critical resources of our customers, but also to put cyberdefense back in the lead, our teams engage in continuous and active security improvements through our products and services. Our products: Quarks Flow (threats detection) and Quarks AppShield (software protection) Our services: Vulnerability research, Vulnerability intelligence, Reverse engineering, Software security and cryptography Our trainings: Reverse engineering, Android Applications for a reverse engineer, iOS Application Security and iOS Internals

Company type: SME

Industry: Computer Hardware & Networking

Founded: 2018

Company size: 51 - 200

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Job description

💼 The Role

We're looking for a Senior Java Developer with strong knowledge of Java internals: bytecode and class loading ; and knowledge in compilation, obfuscation, and runtime behavior. You'll join our QShield team, which builds protection tools for code (Java/C/C++), cryptographic keys, and sensitive data.

Some of our tools rely on bytecode transformation using libraries like ASM, while others interface with native C/C++ code or deal with Android internals.

⚠️ The role is 100% remote but restricted to candidates living in France (for legal and logistical reasons).

We also welcome C/C++ compiler engineers eager to specialize in Java security.

The position is open to permanent contract as well as freelance.

🚀 What You’ll Do

Work on our Java protection product (obfuscation, anti-tamper, etc.)
Write and maintain bytecode transformations with performance and stealth in mind
Write and maintain protection against dynamic instrumentation and tampering
Ensure compatibility with a range of Java runtimes and Android versions
Review code, mentor junior developers, and help maintain high-quality standards

🧠 What We’re Looking For

Required:

5+ years of experience in Java (or C/C++ with a focus on internals/compilation)
Solid understanding of:
Java bytecode
JVM internals and performance implications
Bytecode manipulation libraries (ASM, BCEL, etc.)
Good software engineering practices (design, tests, code reviews)
Fluent in spoken and written English
Able to work autonomously in a distributed (remote) environment
CI/CD and test automation

Nice-to-Have:

Background in application or software security
Experience in reverse engineering or anti-reverse techniques
Familiarity with Android internals / NDK
Build tools: Gradle, Maven
Familiarity with GitLab CI, Git, CMake

✨ Why Join Us?

Work remotely from anywhere in France with flexible hours
Collaborate with experts in security, reverse engineering, and compiler technologies
Contribute to tools that make life harder for attackers
Be part of a tight-knit R&D team where curiosity and initiative are valued