Senior Penetration Tester - The Netherlands TRS · Utrecht ·

Mnemonic; Utrecht; On-site; EUR 90,000 - 130,000; Full time

Benefits offered by this job

Informal environment

Career growth

Conferences & training

Competitive salary

Pension and insurance

Well-being activities

Job summary

Mnemonic is seeking a Senior Penetration Tester to lead advanced security assessments across web apps, APIs, cloud environments, and infrastructure. You will combine hands-on expertise with strategic guidance in projects, mentoring and client interactions.

Ideal candidates have several years in penetration testing, security testing or related fields, with a passion for secure solutions and a proactive, advisory mindset.

Qualifications

• Completed higher technical education, preferably within security or related disciplines.
• Experience in penetration testing, security testing, development, cloud or infrastructure security.
• Ability to independently scope, execute and conclude complex security assessments.
• Hands-on with technology, able to dissect and understand how it works.
• Structured, independent work style with ownership of deliveries and quality.
• Clear communication of complex technical information to technical and non-technical stakeholders.
• Good spoken and written English.

Responsibilities

• Lead and perform advanced vulnerability analyses and penetration tests of web apps, APIs, mobile apps, cloud environments and complex infrastructure.
• Analyse code and architecture to identify design weaknesses, systemic risk and high-impact attack paths.
• Provide concrete and strategic advice on secure architecture and solution design across application, cloud and on-prem environments.
• Assess and secure high-risk areas in cloud deployments (IAM, network segmentation, logging).
• Test and advise on containerised and modern architectures (Kubernetes, microservices, serverless).
• Develop and improve internal tooling, scripts and automation for repeatable security testing.
• Establish and mature routines for efficient handling of vulnerabilities and secure operation.
• Contribute as a senior resource in projects, procurement processes and security reviews.
• Act as a trusted advisor for customers and mentor others.

Skills

Penetration testing

Security testing

Cloud security

Infrastructure security

Secure solutions

Automation tooling

Mentoring

Communication

English proficiency

Education

Higher technical education in security or related

Relevant certifications in security

Job description

Senior Penetration Tester

mnemonic is looking for experienced candidates who combine deep technical expertise with business understanding and strong communication skills.

Have you worked for several years with security or within related disciplines, and want to further develop your professional profile and take a leading role as a trusted advisor within the security profession?

Maybe you have already worked as a penetration tester for a number of years and are looking for greater professional challenges and responsibility. You might also be a developer passionate about secure solutions and building your own testing tools, a cloud or infrastructure specialist with experience from complex IT environments, a technical architect involved in major development or migration projects, or a security analyst who solves “Capture the Flag” competitions as a hobby. Be it applications, cloud platforms or infrastructure, you fundamentally understand how technology works, you pick things apart and put them back together afterwards, and work hands-on to solve demanding problems in creative ways.

As a Senior Penetration Tester, you will combine hands-on technical expertise with strategic understanding, act as a technical authority in projects, and contribute to strengthening both our customers and our internal professional environment.

You will be working with

You will get the opportunity to work with a wide range of tasks, for example:

• Lead and perform advanced vulnerability analyses and penetration tests of web applications, APIs, mobile apps, cloud environments and complex infrastructure.

• Analyse code and architecture to identify design weaknesses, systemic risk and high-impact attack paths.

• Provide concrete and strategic advice on secure architecture and solution design across application, cloud and on-prem environments.

• Assess and secure high-risk areas in cloud deployments, such as Identity and Access Management (IAM), network segmentation and logging.

• Test and advise on containerised and modern architectures, including Kubernetes, microservices and serverless solutions.

• Develop and improve internal tooling, scripts and automation to ensure efficient, repeatable and high-quality security testing.

• Establish and mature routines for efficient handling of vulnerabilities and secure operation.

• Contribute as a senior resource in projects, procurement processes and security reviews.

• Act as a trusted advisor for customers, facilitate technical discussions, and contribute to mentoring and knowledge sharing internally and externally.

What you will bring

We are looking for someone that:

• Has completed higher technical education, preferably within security or related disciplines.

• Has relevant experience within penetration testing, security testing, development, cloud or infrastructure security.

• Has the ability to independently scope, execute and conclude complex security assessments.

• Enjoys working hands‑on with technology, picking things apart to understand how they work.

• Works structurally and independently, and takes clear ownership of deliveries and quality.

• Has the ability to clearly communicate complex technical information to both technical and non‑technical stakeholders, verbally and in writing.

• Has good communication skills in English, both verbally and written.

• Has consultancy experience and understands the customer perspective.

Relevant certifications

• Offensive Security Certified Professional (OSCP)

• GIAC Penetration Tester (GPEN), GIAC Web Application Penetration Tester (GWAPT)

• Certified Cloud Security Professional (CCSP), Certificate of Cloud Security Knowledge (CCSK)

• Security certifications for AWS, Azure or Google Cloud Platform (GCP)

• CISSP, CISA

What we can offer

• An informal and pleasant working environment that provides opportunities for growth, influence and variations in tasks

• Competitive salary, share program and bonus scheme that promotes a long‑term employment outlook, including attractive pension and insurance coverage

• Opportunities for relevant professional training (courses) and conferences

• We place a strong emphasis on workplace well‑being and teambuilding through social activities, events and trips with colleagues. In addition, we have an inclusive environment that promotes work‑life balance and accommodates to families. All our offices are centrally located.

• A workplace that has been ranked as one of the best in Europe for a number of years. In Norway we have been amongst the top 10 workplaces for 10 years in a row.