Senior Security Engineer (Product Security)

As a Senior Security Engineer (Product Security) at Immutable, you join a security team of five reporting to the Head of Security. You'll spend most of your time embedded with product engineering teams across a wide spread of work: web apps and APIs, AWS and GCP infrastructure, and smart contracts where vulnerabilities have direct financial impact. Your mission is central to Immutable's target of fixing 80% of vulnerabilities before they reach production.

What you'll do

• Own the vulnerability management program, including Bugcrowd and Immunefi bug bounties and findings from scanning tools, with a goal of 90%+ SLA compliance on critical and high severity issues
• Own the AI agents that review pull requests for security issues and triage incoming bugs
• Build a security context layer (threat models, asset inventory, past findings) that enables those agents to triage and propose fixes with reduced human input
• Keep threat models and attack graphs current as the product evolves
• Review new services and build threat models with product engineering teams
• Fix security issues in product code alongside engineering teams

What you bring

• Application security depth: you can identify broken auth flows and injection bugs, explain root causes, and implement proper fixes
• Proven ability to ship production code, whether fixing vulnerabilities in others' services or building security tooling from scratch
• Hands-on experience building AI tooling such as agents, automation or internal tools, with clear insight into what worked, what didn't, and how you measured success
• Solid AWS security experience covering IAM, network controls, secrets management, and misconfigurations

Nice to have

• Web3 experience such as wallet, smart contract or dApp security
• GCP, detection and response experience
• Experience running a bug bounty program or findings pipeline end to end
• Deeper detection and response experience or a genuine interest in growing into it

What we offer

• Globally competitive base salary plus contributions to a long-term fund
• Employee Stock Options (ESOP) to share in product success
• Flexible working: Sydney-based employees work hybrid (3 days per week in office); remote team members work from home or access global office hubs via WeWork All-Access pass
• Fresh lunch ordered daily in Sydney CBD office
• USD $500 work-from-home allowance to set up your home office
• USD $600 per annum toward internet and phone usage
• USD $75 per quarter for remote employees to celebrate with local team members
• Up to USD $1,350 per annum for classes, courses, AI tooling or events supporting your growth
• Free online courses via Udemy
• USD $800 per year toward health and wellbeing
• 24/7 access to unlimited counselling for you and your family through our EAP service
• Monthly subsidy and discounted rate with ClassPass, including 1-year free Breethe membership
• Paid parental leave
• 2 additional paid annual leave days at year end
• Paid day off on your birthday
• US employees: medical and 401K insurance support
• Australian employees: access to Novated Leasing for vehicle payments using pre and post-tax dollars

About Immutable

Immutable is the world's fastest-growing game platform, built to power the next generation of games. Founded in 2018 and one of Australia's fastest companies to reach unicorn status, Immutable raised more than AUD $400M at a valuation of AUD $3.5B. More than 700 games build on Immutable; industry leaders like Ubisoft have chosen Immutable as their partner. The product suite spans infrastructure, player engagement, a marketing data platform for studios, blockchain infrastructure including an Ethereum layer-2 network, and Passport, a wallet for players to hold real digital assets.