Detection Engineer

Arobas Personnel is looking for an experienced Detection Engineer for a contract opportunity with one of our clients in Montreal . The Detection Engineer will support the organization’s Splunk-based detection environment , working closely with Incident Response, Cyber Threat Intelligence, SOC, and Red Team stakeholders to strengthen detection coverage and improve the quality of security detections.

Key Responsibilities

🔹 Ensure operational continuity of the Splunk-based detection stack 🔹 Review and implement rule tuning requests from the Incident Response team, including false-positive reduction, logic refinement, and threshold adjustments 🔹 Design, develop, and deploy new Splunk detections based on threat patterns, indicators, and TTPs provided by the CTI team 🔹 Map new and existing detections to MITRE ATT&CK to track detection coverage 🔹 Develop and refine detection content for Purple Team exercises , incorporating identified gaps and post-exercise improvements 🔹 Test and validate detection effectiveness before production deployment, including true-positive validation and noise reduction 🔹 Maintain detection logic under version control and document tuning rationale 🔹 Track and manage work items in Jira 🔹 Participate in handoffs and collaboration sessions with Incident Response, CTI, SOC, and Red Team stakeholders Key Deliverables : 🔹 Tuned and updated Splunk detection rules addressing Incident Response requests, with documented rationale 🔹 New detection use cases covering CTI-identified threat patterns , mapped to MITRE ATT&CK 🔹 Detection content supporting Purple Team exercises , including post-exercise improvements 🔹 Up-to-date documentation of detection logic and coverage gaps 🔹 Work items properly tracked and closed in Jira Must-Have Skills : 🔹 Strong hands-on experience with Splunk , including SPL, correlation searches, dashboards, data models, and detection-as-code workflows 🔹 Proven Detection Engineering experience writing, tuning, and validating SIEM detection rules in a production environment 🔹 Working knowledge of MITRE ATT&CK for threat modeling and coverage mapping 🔹 Familiarity with relevant security telemetry and log sources, including EDR, Windows/Linux/Sysmon, network, and cloud logs 🔹 Experience with Threat Hunting methodologies and CTI-provided IOCs/TTPs, including structured intelligence such as STIX/TAXII or narrative reporting 🔹 Understanding of Incident Response processes and the ability to translate tuning requests into actionable detection rule changes Nice to Have : 🔹 Exposure to Purple Teaming and adversary emulation , including tools or approaches such as Atomic Red Team and Caldera 🔹 Scripting skills with Python and/or Power.

Shell for detection logic, automation, and tooling 🔹 Experience with Git for managing detection content as code 🔹 Experience with Jira in an Agile or operational environment 🔹 Ability to clearly document technical decisions and rationale for handoff to technical teams and management