Key Skills

Job Description

Cyber Security Specialist – Purple Team / API Security Location: Amsterdam, Netherlands Working Model: Hybrid Employment: Full-time employment with Open Solution Providers (OSP) Assignment: Long-term assignment with a leading private-sector financial & banking institution About the Role Open Solution Providers (OSP) is looking for an experienced Cyber Security Specialist to join a long-term client assignment with a leading financial and banking institution in the private sector, based in Amsterdam. We are looking for a security professional with strong Purple Team experience, or a profile with a clearly demonstrated split of approximately 60% Red Team and 40% Blue Team expertise. The successful candidate will work across offensive and defensive security disciplines, with a particular focus on API Security, Application Security and Cloud Security. You will play an important role in identifying vulnerabilities, assessing security risks, strengthening security controls and translating security requirements into practical policies, automation and security guardrails. You will work closely with engineers, architects and security specialists to ensure that APIs and applications are secure, resilient and aligned with organisational security requirements. Key Responsibilities Assess and strengthen the security of APIs and application environments. Perform offensive security activities, vulnerability identification and security testing. Apply defensive security principles to improve detection, prevention and remediation. Translate security standards, controls and best practices into practical security policies. Develop and implement automated security guardrails and business rules. Analyse API and application security findings and assess their severity and criticality. Identify opportunities to improve security controls based on offensive security findings. Work closely with engineering, architecture and security teams. Contribute to API Security strategy, standards and governance. Support the organisation in maintaining secure and resilient digital platforms. Translate complex security requirements into practical and actionable technical solutions. Take ownership of security initiatives and drive them through to implementation. Mandatory Technical Skills & Experience The successful candidate must have strong practical experience across the following areas: Cyber Security & Architecture Strong understanding of cybersecurity principles and security architectures. Strong experience in Cloud Security. Strong understanding of Application Security Architecture. Proven Purple Team experience, or a demonstrable 60% Red Team / 40% Blue Team skillset. Strong understanding of offensive and defensive security practices. API & Application Security Deep expertise in API Security. Strong expertise in Application Security. Strong knowledge of: OWASP Top 10 MITRE CVE Experience assessing API and application vulnerabilities and translating findings into practical security improvements. Authentication & Authorisation Strong hands-on knowledge of: OAuth JWT Session Management mTLS Object-Level Authorisation Attribute-Level Authorisation API Security Platforms Hands-on experience managing or working extensively with at least one of the following API Security platforms is mandatory: Akamai Noname Salt Security Cequence Security Policy & Automation Ability to translate complex security requirements into practical platform policies. Experience implementing automated security guardrails. Ability to translate security findings into actionable improvements to security policies and business rules. Strong analytical capability when assessing security findings, risk and criticality. Professional Profile We are looking for someone who combines strong technical security expertise with a pragmatic, delivery-focused approach. You should have: Strong analytical and problem-solving skills. Excellent communication skills. A proactive mindset. The ability to work independently and take ownership. The ability to communicate effectively with engineers, architects and security specialists. Experience operating in complex enterprise environments. A collaborative mindset and the ability to work effectively across both offensive and defensive security functions. Assignment & Employment This is a full-time position with Open Solution Providers (OSP). You will be employed by OSP and placed on a long-term assignment with our client, a leading financial and banking institution in the private sector. If you are an experienced Cyber Security Specialist with strong Purple Team, Red Team/Blue Team, API Security and Application Security expertise, we would like to hear from you. Please ensure your CV clearly highlights your experience with Purple Team / Red Team / Blue Team, API Security, Application Security, Cloud Security, OWASP, MITRE, OAuth, JWT, mTLS, and Akamai Noname, Salt Security or Cequence.

Core Responsibilities

The specialist will assess and strengthen the security of APIs and application environments by performing offensive and defensive security testing. They will also translate complex security requirements into practical policies and automated guardrails while collaborating with engineering and architecture teams.

Requirements

Candidates must have strong practical experience in Purple Team operations, API security, and cloud security architectures. Proficiency in security standards like OWASP and MITRE, along with hands-on experience in API security platforms, is mandatory.