Senior Software Engineer, Security

The Role

What You’ll Own

• Design and ship security improvements across the Linktree product: authentication and authorisation, session and token handling, secrets management and third-party access.
• Build the detection and response capability for the product surface - abuse, account takeover, scraping and fraud - so problems surface before creators report them.
• Threat model new and existing systems with the squads that own them, and turn the output into prioritised, shipped work.
• Own the internal tooling and paved paths that make it easy for every other engineer to build securely by default.
• Triage and remediate vulnerabilities from internal findings, bug bounty and pen tests, and fix the class of problem rather than the instance.
• Partner with Engineering, Product and Trust & Safety on where to harden and where a control costs more in creator friction than it buys in risk reduction.
• Bring AI into how you build, and use it to move faster on reviews, migrations and investigation - while staying clear-eyed about what it gets wrong.
• Raise the security bar around you through review, pairing, documentation and mentoring.

Who We’re Looking For

• 4+ years of professional software engineering experience, with meaningful time spent on security, infrastructure, identity or another domain where getting it wrong is expensive.
• Strong full-stack skills across our core stack: TypeScript, Node.js, React, GraphQL, PostgreSQL or MySQL and AWS, with the ability to move across layers to ship a fix end-to-end.
• Working knowledge of application security fundamentals: the OWASP Top 10, authentication and authorisation, secrets management, cryptography in practice, and the common attack classes against consumer platforms.
• Experience threat modelling a real system and turning the output into shipped work, rather than a document nobody reads.
• A track record of shipping changes to a high-traffic, critical path safely - feature flags, staged rollouts, migrations and backwards compatibility.
• Fluency with AI-assisted development (Claude, Cursor, Codex and similar), including how to prompt, validate and refine what these tools produce - and where they introduce risk.
• A pragmatic instinct for balancing security against user experience, and the confidence to make that trade-off explicit with Product and Engineering.
• Able to influence engineers outside your own team without relying on mandate, and to write decisions down clearly.
• Based in Los Angeles or San Francisco, working hybrid from one of our offices.

Where and How We Work

How we’ll help you thrive

• An annual wellbeing allowance to use on things like (but not limited to) fitness memberships, development courses, childcare, travel, charitable donations, pet insurance, home office set up - the choice is yours!
• 100% coverage (and 80% for your dependents) of your monthly premiums for medical, dental, vision, disability and life insurance for US-based employees.
• Employer contribution towards your retirement.
• Generous time off for vacation, holidays, parental leave, volunteer time and other categories.
• Employee Stock Option Program - we want each and every employee to share in the company’s success as we go further together.

Our Story