Senior Security Engineer: Threat Detection & Incident Response

LemFi; Dublin; Hybrid; EUR 110,000 - 140,000; Full time

Job summary

LemFi in Dublin is seeking a Senior Security Engineer to own how we protect our people and products from the inside. You will build controls, write detections and run incidents, reporting directly to the CTO.

It’s a small team, so you’ll shape the playbook and own security outcomes across endpoints, identities and internal tools. You’ll drive threat detection, incident response and intelligence-driven controls, with a bias toward automation, AI and ML to sharpen detections.

Qualifications

• 5+ years of hands-on security work across incident response, detection engineering, threat intelligence or security engineering.
• Hands-on experience running endpoint protection or EDR at scale across Windows and macOS.
• Strong identity and access management experience with directories, SSO and MFA (Entra ID, Okta, Google Workspace).
• Led real incidents end to end, including forensic investigation on endpoints.
• Written detections in a SIEM that caught real activity and minimized false positives.
• Proficient in Python or Go to build tooling and automate work.
• Practical use of AI or ML in security work with demonstrated value.

Responsibilities

• Own endpoint protection across all laptops and devices (EDR, hardening, patching, containment).
• Manage identity and access (SSO, MFA, privileged access, joiner/leaver flows, access reviews).
• Secure email, collaboration, and SaaS with phishing defence and internal visibility.
• Build detections and perform threat hunting across endpoints, identity, and internal systems.
• Lead incident response from first alert through forensics and root cause analysis.
• Turn threat intelligence into detections and controls; improve coverage.

Skills

Incident response

Threat intelligence

Detection engineering

Security engineering

Python

Go

AI/ML in security

Tools

EDR

SIEM

Entra ID

Okta

Google Workspace

Job description

LemFi in Dublin is seeking a Senior Security Engineer to own how we protect our people and products from the inside. You will build controls, write detections and run incidents, reporting directly to the CTO.

It’s a small team, so you’ll shape the playbook and own security outcomes across endpoints, identities and internal tools. You’ll drive threat detection, incident response and intelligence-driven controls, with a bias toward automation, AI and ML to sharpen detections.