Senior Information Security Engineer

Optiver; Sydney; On-site; AUD 150,000 - 210,000; Full time

Benefits offered by this job

Performance‑based bonus structure

Diverse and intelligent peers

Training and mentorship opportunities

Daily breakfast and in‑house barista

Gym membership and weekly chair masses

Company social events

Job summary

Optiver Sydney is seeking a Senior Information Security Engineer to protect and improve our global systems, including AWS/M365 and on‑prem infrastructure. You will lead risk mitigation, incident response, and security automation to reduce manual work while embedding best practices across the organization.

You will work with engineering and business teams, perform vulnerability assessments, harden configurations, and help scale security across cloud and workloads.

Qualifications

• 5+ years in information security or technical engineering.
• Experience with Windows and Linux environments and common security tech.
• Scripting in PowerShell and Python.
• Knowledge of identity management concepts and modern access control patterns.
• Experience using security tooling such as EDR, SIEM, SOAR, CASB.
• Experience securing workloads on-prem and in IaaS (cloud).
• Familiarity with vulnerability management tools and secure configurations.
• Experience with data protection and DLP solutions (e.g., Microsoft Purview).

Responsibilities

• Monitor daily security operations, identify threats, investigate alerts, and respond to incidents across cloud and on‑prem environments.
• Strengthen Microsoft 365 and Entra ID security through CA, MFA, PIM, Defender for Endpoint/Identity/O365, and tenant hardening.
• Build and maintain security automation using Python and PowerShell to reduce manual work and improve detection.
• Integrate systems using APIs (Graph API, REST) to enhance security workflows.
• Perform vulnerability assessments, review configurations, and develop practical mitigations.
• Contribute to incident response activities including investigation, containment, and remediation.
• Collaborate with engineering, technology, and business teams to embed security best practices.

Skills

Analytical thinking

PowerShell scripting

Python scripting

Windows & Linux proficiency

Identity management concepts

Tools

EDR

SIEM

SOAR

CASB

Job description

Optiver is a global market maker founded in Amsterdam, with offices in London, Chicago, Austin, New York, Sydney, Shanghai, Hong Kong, Singapore, Taipei and Mumbai. Established in 1986, today we are a leading liquidity provider, with close to 2,000 employees in offices around the world, united in our commitment to improve the market through competitive pricing, execution and risk management. By providing liquidity on multiple exchanges across the world in various financial instruments we participate in the safeguarding of healthy and efficient markets. We provide liquidity to financial markets using our own capital, at our own risk, trading a wide range of products: listed derivatives, cash equities, ETFs, bonds and foreign currencies.

Who We Are

Optiver is a global market maker founded in Amsterdam, with offices in London, Chicago, Austin, New York, Sydney, Shanghai, Hong Kong, Singapore, Taipei and Mumbai. Established in 1986, today we are a leading liquidity provider, with close to 2,000 employees in offices around the world, united in our commitment to improve the market through competitive pricing, execution and risk management. By providing liquidity on multiple exchanges across the world in various financial instruments we participate in the safeguarding of healthy and efficient markets. We provide liquidity to financial markets using our own capital, at our own risk, trading a wide range of products: listed derivatives, cash equities, ETFs, bonds and foreign currencies.

What You’ll Do

We are seeking a motivated, hands‑on Senior Information Security Engineer to join our security team. In this role, you will help protect, monitor, and continuously improve the security of our global systems including cloud (AWS and M365) and on‑premises infrastructure. You’ll play a central part in risk mitigation, incident response, automation of security operations, and embedding security best practices across our organisation. An engineering mindset, attention to detail, and a preference for pragmatic solutions are essential to keeping our systems operating.

Main responsibilities include:

• Monitor daily security operations, identify threats, investigate alerts, and respond to incidents across cloud and on‑prem environments.
• Strengthen Microsoft 365 and Entra ID security through Conditional Access, MFA, PIM, Defender for Endpoint/Identity/O365, and tenant configuration hardening.
• Build and maintain security automation using Python and PowerShell, with a strong focus on reducing manual processes and improving detection and response.
• Integrate systems using APIs (Graph API, REST, etc) to enhance security workflows.
• Perform vulnerability assessments, review system configurations, and develop practical mitigation strategies.
• Contribute to incident response activities including investigation, containment, communication, and remediation.
• Work closely with engineering, technology, and business teams to embed security best practices.

Who You Are

Optiver needs our next Information Security Engineer to have:

• At least 5 years experience in an information security or technical engineering role.
• Ability to apply analytical thinking to technical problems within a fast‑moving environment.
• Comfortable with both Windows and Linux environments; familiarity with common security technologies (firewalls, endpoint protection, log management, vulnerability scanning, network security).
• Solid scripting skills in PowerShell and/or Python
• Knowledge of secure Identity Management, authentication principles, and modern access control patterns.
• Experience using security tooling such as EDR, SIEM, SOAR, CASB, etc
• Experience securing workloads running both on‑premise (bare‑metal / container) and on IaaS platforms.
• Familiarity with identity lifecycle processes, RBAC, PAM, and privileged identity controls.
• Understanding of vulnerability management tools (Nessus/Tenable, RunZero, etc) and secure configuration standards.
• Experience with data protection, DLP, or information protection solutions (e.g., Microsoft Purview, DLP rules, classification/labelling).

Please note that we welcome interest from candidates with varying levels of experience; many successful candidates do not meet every single requirement.

What You’ll Get

You’ll join a culture of collaboration and excellence, where you’ll be surrounded by curious thinkers and creative problem solvers. Driven by a passion for continuous improvement, you’ll thrive in a supportive, high‑performing environment alongside talented colleagues, working collectively to tackle some of the most complex problems in the financial markets.

In return for your expertise, you will have access to a range of Optiver perks, including:

• A performance‑based bonus structure unmatched anywhere in the industry.
• The chance to work alongside diverse and intelligent peers in a rewarding environment.
• Training, mentorship and personal development opportunities.
• Daily breakfast, lunch and an in‑house barista.
• Gym membership plus weekly in‑house chair massages.
• Regular social events, including a company trip every two years.

Optiver is committed to diversity and inclusion. We encourage applications from candidates of all backgrounds, and welcome requests for reasonable adjustments during the process.