Expert Operational Security Engineer - Mainframe

A major Belgian bank in Brussels needs an Expert Mainframe Operational Security Engineer in IT Security Production. You keep the Mainframe estate secure, compliant and resilient: set and enforce security standards, manage RACF and related controls, support encryption and HSM work, assess new Mainframe products before go-live, and help resolve security incidents with minimal disruption.

Responsibilities: Manage user permissions and access for systems outside IAM without blocking operations; Manage RACF database content manually or via automation; Create clear security documentation and standards for delivery teams; Handle encryption tasks from importing certificates to configuring HSM agents; Assess security of new Mainframe products before go-live; Resolve security incidents with the squad and support auditors with compliance evidence.

Business experience: Cybersecurity experience with hands-on Mainframe expertise (mandatory); Financial sector experience (preferable).

Functional experience: At least 10 years of relevant experience (mandatory); RACF Security Administrator certification (mandatory); On-call participation for critical job failures (~1 week per month including weekends/holidays) (mandatory).

Technical experience: RACF and surrounding utilities (mandatory); Mainframe architecture and basic tools (JCL, ISPF, REXX, SDSF) (mandatory); Role-based security modelling (mandatory); AT-TLS and certificates; Public Key Infrastructure and Mainframe CryptoCards (mandatory); Security of DB2, IMS and MQ; job scheduling; Mainframe subsystems security (mandatory); Unix System Services (mandatory); zSecure product suite; Control-M; COBOL; Endevor (preferable).

Language requirements: English (mandatory, good speaking/reading/writing); Dutch (good, not mandatory); French (good, not mandatory).

Soft skills: Analytical, critical thinking, problem-solving, creativity, agile teamwork with ownership, proactive risk spotting in high-volume environments.

Location: Brussels (5 min walk from Central Station) - 50% on site / 50% homeworking. Travel N/A. Remote/telework from Belgium only. Start date: 2026-11-02. Duration: 12 months. Estimated daily rate (EUR): 720 - 850. Education: Bachelor's degree.