Junior Penetration Tester
Sentrium is a UK-based cyber security consultancy headquartered in London. We specialise in ethical hacking, penetration testing, and vulnerability assessments, supporting a wide range of organisations across the UK public and private sectors.
About the role
We’re looking for a Junior Penetration Tester to join our growing team. You’ll work alongside highly experienced consultants on a diverse range of projects, developing both your technical and professional skills. With hands on experience and daily mentoring, you’ll learn how to deliver penetration testing engagements from start to finish, gradually taking on greater responsibility as your skills and confidence develop.
Our aim is to help you grow into a consultant who can confidently deliver projects independently, while knowing that support and guidance are always available. As part of our close-knit team, you’ll have the opportunity to learn directly from experienced testers and gain exposure to a broad range of technologies, clients and testing methodologies.
You’ll also contribute to wider company activities such as internal research, tool development and technical authoring. We value adaptability, initiative and a willingness to take ownership, alongside strong teamwork and communication skills.
This is an excellent opportunity for someone looking to start their career in penetration testing and develop into a well-rounded consultant within a supportive, experienced team.
About you
We’re looking for someone who:
- Has a strong technical foundation, gained through a degree, previous role, or self-directed learning.
- Is eager to learn and develop their skills across a wide range of testing projects.
- Communicates clearly and confidently in both written and spoken English.
- Works well in a team, but is also comfortable managing tasks independently.
- Brings curiosity, initiative, and adaptability to a fast-moving environment.
Specific qualifications (e.g. OSCP, CREST, CRT) are welcome but not required, we’re more interested in your ability, mindset, and potential.
What we offer
- A varied workload with opportunities to build experience across multiple sectors and technologies.
- Daily mentoring and professional development support.
- Funding for training and recognised industry qualifications.
- Competitive salary and benefits.
- Flexible, remote-first working.
- Generous holiday allowance and positive work-life balance.
Working setup
Technical team
Remote (UK)
About Sentrium
Founded in 2019, we’ve grown steadily through reputation, not volume. Our team is small but highly skilled, giving clients the flexibility of a boutique consultancy backed by the credibility of CREST-accredited expertise. At Sentrium, curiosity and collaboration fuel everything we do, whether that’s uncovering vulnerability, developing new techniques, or helping clients strengthen their security with confidence.
Grow with Sentrium
Working at Sentrium means being part of a consultancy that prizes expertise, clarity, and trust.
Here’s what you can expect:
Recognition and career growth
Professional development
Remote-first flexibility
Team connection
How to apply
If you’re enthusiastic about cyber security and want to join our team, send your CV and cover letter to [email protected]
Applications via job boards will not be reviewed. Applicants must have the right to work in the UK. Strictly no agencies.
People at Sentrium
Working at Sentrium is the best decision I ever made. There is never a dull moment, and no clock watching, every day brings its own technical challenges. The work is rewarding and enriching, made even better when you share your successes with a likeminded team who are always supportive.
Phil Condon
As one of the newer members at Sentrium, I’ve been trusted from the start which has pushed me to grow quickly. The best part is the team. Everyone has your back, you never feel on your own. The trust and support around me has helped me grow and develop faster than I expected.
Theklis Stefani
I’ve worked with Sentrium Security since the beginning, and it’s been an absolute pleasure working with the team over the past six years. A lot has changed during that time, but what’s stayed consistent is the drive to be the best, which shows in everything the company does.
James Drew