IT Offensive Security Engineer III (Must Reside in Texas)

Randolph-Brooks Federal Credit Union•San Antonio, TX

1d•Hybrid

About The Position

Randolph-Brooks Federal Credit Union is seeking an experienced Offensive Security Engineer III to join its IT Security team. The role leads complex, intelligence-informed adversary emulations to assess how effectively the organization’s people, processes, architecture, and technology withstand realistic, multi-stage attacks. Campaigns may cover identity, endpoints, networks, applications, APIs, cloud platforms, data environments, software delivery systems, and other authorized surfaces. Controlled human-factor and physical scenarios may be conducted only with explicit approval. The engineer evaluates attack-path viability and the effectiveness of preventive, detective, responsive, and recovery controls, and translates demonstrated compromise paths into improvements across security and engineering. The role provides technical and engagement leadership, develops offensive tooling and infrastructure, manages operational risk, and coordinates with threat intelligence, SOC, incident response, security engineering, legal, privacy, physical security, and business stakeholders. It also advances offense and defense through purple-team collaboration, detection validation, reporting, mentorship, and repeatable assessment methods. The position offers a hybrid schedule (remote/onsite) after a training period, which may vary. Training takes place at the RBFCU Administrative Service Center in Live Oak, Texas. Applicants must reside in Texas and be able to perform all work from a home in Texas. Home work requirements include meeting RBFCU’s minimum internet connection requirements, having a reliable internet provider and the ability to connect directly to the modem by Ethernet, and providing a safe, suitable, distraction-free workspace.

Requirements

Bachelor’s degree in Computer Science, Management Information Systems, Cybersecurity, Information Technology, or a related field, or an equivalent combination of education and experience.
Minimum 3–5 years conducting adversary emulation, penetration testing, red team operations, or advanced security assessments.
Deep hands-on experience leading multi-stage adversary emulations and complex assessments across several enterprise technology domains.
Advanced knowledge of identity attacks, endpoint tradecraft, network protocols, application and API exploitation, cloud attack paths, persistence, command and control, evasion, and data-access techniques.
Experience designing rules of engagement, managing testing risk, coordinating deconfliction, protecting sensitive data, and making stop-work decisions during live exercises.
Production-quality engineering experience using Python, Go, C#, C/C++, Rust, PowerShell, JavaScript, APIs, infrastructure automation, or comparable technologies.
Experience developing or modifying offensive tools, payloads, infrastructure, attack automation, and validation methods while maintaining operational security.
Advanced technical judgment to balance realism, stealth, evidence, business impact, legal and ethical boundaries, safety, and operational continuity.
Strong communication, facilitation, and stakeholder-engagement skills, including constructive debriefs and concise communication to senior leadership.
Must reside within Texas and be able to perform all work from a home in Texas.
Must have a reliable home internet provider, meet RBFCU’s minimum internet connection requirements, and be able to hard-wire a connection to the modem.
Must provide a safe, suitable, distraction-free home workspace.

Nice To Haves

Experience emulating advanced threat actors in hybrid and multi-cloud environments, identity systems, software supply chains, data platforms, AI systems, or critical infrastructure.
Experience with advanced application exploitation, exploit development, malware research, reverse engineering, cloud red teaming, wireless testing, or hardware security.

Responsibilities

Lead complex, multi-domain adversary-emulation campaigns targeting critical services, high-value assets, privileged identities, cloud control planes, applications, data, and software delivery systems.
Translate threat intelligence and business context into campaign objectives, adversary profiles, attack hypotheses, target selections, techniques, success criteria, and measurable defensive outcomes.
Design engagement plans, rules of engagement, safety controls, communications, deconfliction, escalation paths, data-handling requirements, and technical workstreams.
Execute and supervise advanced attack activity involving stealth, persistence, identity compromise, lateral movement, cloud privilege escalation, application exploitation, data access, and objective demonstration.
Lead controlled social-engineering, physical, wireless, third-party, or assumed-breach scenarios when explicitly approved by the required authorities.
Develop custom tooling, implants, payloads, test harnesses, automation, redirectors, infrastructure, and operational-security practices appropriate to authorized objectives.
Evaluate defense-in-depth performance across prevention, identity, segmentation, telemetry, detection, investigation, containment, eradication, recovery, and resilience.
Lead purple-team exercises and convert engagement observations into detections, hunts, playbooks, architecture improvements, control validation, and remediation priorities.
Produce executive and technical narratives connecting attack paths and defensive gaps to business risk, systemic causes, and prioritized corrective actions.
Mentor offensive and defensive engineers, conduct technical reviews, and lead lessons-learned activities to improve engagement safety, realism, repeatability, and impact.
Define engagement strategy, technical methods, safety controls, priorities, and deliverables for complex campaigns.
Build alignment among offensive security, SOC, incident response, engineering, threat intelligence, legal, privacy, physical security, risk, and leadership.
Lead significant engagements, set technical and safety expectations, and improve offensive and defensive quality.