Senior Penetration Tester - Application Security

Ready to unhack the planet? At Syndis, we're expanding our offensive security team in Stockholm, Sweden and looking for an experienced hacker who wants to do more than just another penetration test. We want you who doesn't just run vulnerability scanners, we want you who wants to find your own. Someone who can challenge conventional thinking, drive innovative research, and still get excited about finding that one vulnerability nobody else noticed. If you love breaking into systems and chaining findings to show what an attacker can actually achieve, this is home. We are hackers at heart. The role

• Hack things. Perform advanced penetration tests and security audits across applications, APIs, infrastructure, and complex environments. Find vulnerabilities that automated tools simply won't
• Leverage and write your own tooling, research new attack paths and continuously sharpen our offensive methodologies
• Work closely with engineering and executive teams, delivering clear, actionable reports written for people who actually build and secure systems
• Lead and inspire. Help build, mentor, and develop our offensive security team. Share knowledge, challenge assumptions, and help others become better hackers

What you’ll bring

• Strong hands-on (minimum 3 years) experience in penetration testing, application security, and security audits
• The ability to lead, mentor, and inspire other hackers
• A passion for vulnerability research, creative problem-solving, and continuous learning
• Strong written and communication skills in Swedish and English
• Swedish citizenship and a clean criminal record are required for this role
• Relevant certifications preferred, such as OSWA, OSWE or CREST. However, curiosity, creativity, and actual hacking skills matter more
• Knowledge of LLM-driven tools in application security is a plus

Bonus points: CVE discoveries, security research, CTFs, bug bounties, open-source contributions, or certifications such as OSCP, OSWE, OSWA, and CREST What we offer We aren’t fans of checkbox pentests, compliance-driven box-ticking, or running the same vendor script year after year. At Syndis, we believe real security is built by people who build their own tools, think like real adversaries and focus on business impact. You care about the outcome of the test and helping clients fix the root cause, not just handing over a massive report. We offer challenging application security projects, ownership of your assessments and experienced colleagues who share their knowledge. You’ll find an inclusive, supportive culture with flexible working hours, excellent training and career development and great social events! Interested? Ready to unhack the planet with us? Apply with your CV and cover letter at syndis.com/careers. We’d love to hear about YOU and why you’d like to join Syndis. The application deadline is November 20th, 2026. For questions about the role, contact Pavel Chen, Director of Offsec (pavel@syndis.com), Eva Demireva, Chief Human Resource Manager (eva@syndis.com) and Petra Klein, Managing Director Sweden (petra.klein@syndis.com)