Senior Full Stack Engineer, Authentication

Linktree; Melbourne; Hybrid; AUD 150,000 - 190,000; Full time

Benefits offered by this job

Wellbeing allowance

Medical/Dental/Vision insurance

Retirement contribution

Generous paid time off

Employee stock option program

Job summary

Linktree in Melbourne (VIC) / Sydney (NSW) is seeking a Senior Full Stack Engineer to join the Auth team, owning signup, login, social auth, session lifecycles and MFA. You’ll work across TypeScript, Node.js, React, GraphQL and AWS, partnering with Security and Product to harden and simplify the user sign-in experience.

This role emphasizes ownership of a critical surface, applies AI-assisted development, and includes mentoring as the Auth team grows.

Qualifications

• 4+ years of professional software engineering experience, ideally including auth/identity/platform work.
• Strong full-stack capabilities across TypeScript, Node.js, React, GraphQL, PostgreSQL or MySQL and AWS.
• Knowledge of authentication fundamentals: OAuth 2.0, OIDC, JWTs, session management, MFA.
• Experience shipping changes to high-traffic, critical-path systems with feature flags, migrations & backwards compatibility.
• Familiarity with AI-assisted development (prompting, validation, refinement).
• Practical balance of security and user experience, with clear trade-off discussions with Product/Security.
• Clear communicator across product, design, security, and multiple time zones; hybrid Melbourne/Sydney work.

Responsibilities

• Build and ship authentication and identity experiences: signup, login, social auth, account recovery and MFA.
• Own services behind them end-to-end: session and token lifecycle, revocation, rate limiting, APIs.
• Partner with Security to harden the auth surface and with Product to balance friction and conversion.
• Extend identity and access for business accounts and Workspaces, incl. SSO.
• Keep surface observable: instrumentation, alerting, dashboards for auth reliability.
• Incorporate AI to accelerate migrations, tests and investigations.
• Mentor engineers, engage in code reviews and promote best practices.

Skills

TypeScript

Node.js

React

GraphQL

PostgreSQL

MySQL

AWS

Auth / Identity

4+ years experience

OAuth 2.0

OIDC

JWTs

MFA

AI-assisted development

Security vs UX balancing

Tools

PostgreSQL

MySQL

AWS

GraphQL

Job description

Senior Full Stack Engineer

Melbourne, VIC • Sydney, NSW

Engineering

Remote • Hybrid

Full-time

The Role

We’re looking for a Senior Software Engineer to join the Auth team — the group that owns how 70+ million people get into Linktree and stay safely signed in. Authentication is the first thing every Linker touches and the one surface that has to work every single time, across social login, email, sessions, tokens and the business-account access that sits on top of them.

You’ll work the whole path: the login and signup flows creators see, the services and APIs behind them, the session and token lifecycle, and the observability that tells us something is wrong before a Linker does. You’ll be hands‑on across TypeScript, Node, React and AWS, and you’ll partner closely with Product, Security and the platform teams to decide where to harden, where to simplify, and where a small change in friction moves conversion for tens of millions of people.

This is a role for someone who likes owning a critical, unglamorous surface and making it excellent. Every improvement you ship removes a reason someone can’t get to their own digital presence — and helps Linktree achieve our mission: to empower anyone to curate and grow their digital universe.

What You’ll Own

• Build and ship the authentication and identity experiences Linkers touch first: signup, login, social auth, account recovery and multi-factor.
• Own the services behind them end-to-end — session and token lifecycle, revocation, rate limiting, and the APIs other squads depend on.
• Partner with Security to harden the auth surface, and with Product to keep friction honest so login conversion improves rather than degrades.
• Extend identity and access for business accounts and Workspaces, including the path toward SSO.
• Keep the surface observable: instrumentation, alerting and dashboards that catch auth failures before Linkers report them.
• Bring AI into how you build, and use it to move faster on migrations, tests and investigation.
• Raise the bar around you through review, pairing and documentation, and mentor engineers as the Auth team grows.

Who We’re Looking For

• 4+ years of professional software engineering experience, ideally including time on an auth, identity, platform or payments‑adjacent team.
• Solid 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 feature end‑to‑end.
• Working knowledge of authentication and identity fundamentals: OAuth 2.0, OIDC, JWTs, session management, MFA and the common attack classes.
• Experience 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.
• A pragmatic instinct for balancing security against user experience, and the confidence to make that trade‑off explicit with Product and Security.
• Clear communicator who works well with product, design and security partners across Melbourne, Sydney and other time zones.
• Able to work from our Melbourne or Sydney office on a hybrid basis.

Linktree is committed to providing a fair and competitive compensation package including cash, equity, and benefits. Final offers depend on multiple factors including location, experience, expertise, and role scope, and may vary from the range listed.

Our Story

We’re on a mission to empower anyone to curate, grow, and monetize their digital universe. We created the “link in bio” category — and we’re just getting started. From creators, artists, and entrepreneurs to global brands, we’re redefining how people connect with their communities, showcase their content and promote products — all in one link.

Today, a community of 70+ million use Linktree, including icons like Adidas, TikTok, the UN Environmental Program, The NFL, Manchester United, World Central Kitchen, Sabrina Carpenter, Olivia Rodrigo, and Selena Gomez. With 48,000 new accounts created every day, Linktree is the fastest-growing leader in our space.

We’ve teamed up with some of the world’s biggest platforms including TikTok, Snap, YouTube, GoFundMe, Spotify, Google, Stripe, Reddit, Laylo, and Kajabi, to unify Linkers’ digital spaces, and we partner with retail brands Amazon, Lululemon, Nike, Target, Sephora, Lululemon, and more to share products they love.

We’re a tight‑knit, passionate team building best‑in‑class tools that make online presence simple, powerful, and yours. If you're excited by the idea of shaping a new category, setting the standard, and making space for everyone to be seen and succeed, we’d love to meet you.

Where and How We Work

We're a global, diverse team spread across continents with offices in London, Los Angeles, Melbourne, and San Francisco. We work together flexibly and you can choose the setup that works best for you: fully remote or a hybrid mix of office and home.

We offer autonomy in how you structure your days and weeks. While we’re mindful of time zones and occasionally collaborate outside the typical 9–5, we lean into async work to keep things flowing. Our culture is family‑friendly and Zoom‑casual where kids, pets, and delivery drivers are welcome.

How we’ll help you thrive

Our approach to benefits considers the whole person and the unique contributions they bring to Linktree. We want the experience at Linktree to be one that enables people to truly thrive so we can Go Further Together (one of our values). Some ways we support you:

• 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.

At Linktree, we believe in promoting a culture that celebrates unique backgrounds, talents, and experiences, and we’re proud to be an equal‑opportunity workplace. We are creating an inclusive workplace where every individual feels valued, respected, and has equal opportunities to thrive. Linktree welcomes all people regardless of sex, gender identity, race, ethnicity, disability, pregnancy, age, or other lived experience.