Senior Software Engineer - Identity Core

About Us Perk (formerly TravelPerk) is the intelligent platform for travel and spend management. Built to tackle the time-consuming, manual work that gets in the way of real work, our tools automate everything from travel bookings to expenses, invoice processing, and more. By eliminating this shadow work that wastes hours, erodes morale, and saps innovation, we’re on a mission to power real work, with real impact. We’re trusted by more than 10,000 companies worldwide, including Wise, On Running, Breitling, and Fabletics, and we’re tackling the 7 hours of lost productivity per employee each week, a $1.7 trillion problem . Founded in 2015, Perk has grown into a global company of more than 1,800 people across 12 offices globally, with headquarters in London and Boston. We combine innovation, control, and simplicity to transform how businesses work and how people feel at work. At Perk, we’re driven by our values, like being an owner, delivering a 7-star experience, and working as one team. We value curiosity, purpose, and mindset, not just knowledge, to unlock the power in your potential. Our talent team brings together leading minds from the travel and SaaS industries, representing over 70 countries. If you’re excited about having a real impact and shaping how millions of people experience work, we’d love you on the team. Visit www.perk.com to learn more. Are you a Software Engineer who believes security should be invisible to users but rock-solid underneath? At Perk, our Identity Core squad owns the authentication and authorisation systems that protect our platform and its 10,000+ customers. You will deliver robust and scalable identity, authentication, and user management solutions, ensuring security and ease of integration for internal teams and external partners, serving as the cornerstone of secure and seamless user experiences across the organisation and its partner ecosystem. We prioritise autonomy and pragmatism, giving you the space to solve complex problems without unnecessary friction. Engineering excellence here is measured by the reliability and simplicity of the systems you build to power a global platform. The Squad You’ll join a cross-functional squad where you have real ownership of Perk’s identity and authentication domain, a genuine say in what gets built, and the autonomy to make it happen. You’ll work closely with our platform and security teams to set the standard for how identity is handled across the whole organisation. AI at Perk AI is embedded in how we work and what we build. On the engineering side, it spans the whole workflow: our Notion, Jira, GitHub and Slack are AI-connected so you get up to speed fast, and day-to-day it helps with specifying features, writing and reviewing code, and automated AI PR review on every pull request. We also embrace agentic coding, using AI as an active collaborator, not just a prompt-by-prompt co-pilot. We expect candidates to use AI tools in our coding interviews. Some examples of what it means to be a Senior at Perk Shape the bigger picture. You’ll contribute to the identity and security roadmap alongside your PM and EM — defining not just how we implement auth, but how Perk’s identity platform should evolve to support SSO, enterprise provisioning, and developer-facing integrations at scale. Architect for today and tomorrow. You’ll write design documents for significant changes to our auth systems, balancing security rigour with developer experience. You’ll be a guardian of technical quality — spotting where we need to harden, modernise or simplify our identity stack. Lead across boundaries. Auth touches every squad at Perk. You’ll set consistent patterns for how identity is handled across the organisation, contribute to our engineering guilds, and work with architects on solution discovery for cross-squad identity initiatives. Raise the bar for everyone around you. You’ll mentor, give thoughtful code review feedback, and model what great security-first engineering looks like in practice. You’ll help the team grow its depth in auth protocols, threat modelling and system design. Desired skills and experience We know the best person for this role might not tick every box below. If you're excited about the problem and bring most of these skills, we'd encourage you to apply. Product Leadership: Translates complex business goals into technical roadmaps; de-risks ambiguous projects through spikes and prototyping. System Architecture: Architects scalable, evolvable identity systems — thinking carefully about performance, failure isolation, security boundaries and long-term maintainability. Security-First Engineering: Oversees operational security including secrets hygiene, dependency risk and threat modelling. Treats security as a first-class engineering concern, not a compliance checkbox. Developer Platform Thinking: Understands that the identity layer is a platform consumed by other engineers. Designs for developer experience, clear abstractions and well-documented APIs. Backend Excellence: Engineers sophisticated backend solutions involving API design, token lifecycle management, caching strategies and complex data models for identity at scale. Technical Standards: Defines and upholds engineering excellence including CI/CD, testing strategies (including security testing) and coding standards. Operational Maturity: Leads observability and on-call practices for security-critical systems; defines SLOs, manages incident response and conducts blameless post-mortems. Mentorship & Influence: Levels up the engineering organisation through active mentorship, design reviews and influencing the roadmap with technical insight. AI-Driven Development: Experience with or strong interest in modern AI-augmented workflows and agentic coding. How We Work At Perk, we take an IRL-first approach to work, where our team works together in-person 3 days a week. As such, this role requires you to be based within commuting distance of our hubs. We fundamentally believe in the value of meeting in real life to improve connectivity, productivity, creativity and ultimately making us a great place to work. For certain roles, we can help with relocation from anywhere in the world, English is the official language at the office. Please submit your resume in English if you choose to apply. Do not forget to submit an updated portfolio and/or resume. Perk is a global company with a diverse customer base, and we want to make sure the people behind our product reflect that. We’re an equal opportunity employer, which means you’re welcome at Perk regardless of how you look, where you’re from, or anything else that makes you, well, you. Protect Yourself from Recruitment Scams All official communication from Perk will always come from email addresses ending in @ perk.com or @ externalperk.com , our verified social media channels, or recruiters listed on our official LinkedIn page. We will never ask you to pay for equipment, training, or fees, request sensitive personal information such as bank details early in the process, or communicate through unofficial apps like WhatsApp, Telegram, or Signal. If you receive a message claiming to be from Perk that seems suspicious, please do not respond. Forward it to security [at] perk .com , and we will confirm whether it is legitimate.