Senior Engineer, Authentication and Authorization

<h2><strong>Intro</strong></h2> <p>At Pleo, we’re on a mission to revolutionise the way businesses manage company spending. No more outdated processes, clunky spreadsheets, or frustrating delays – we believe spend management should be seamless, empowering, and surprisingly effective for finance teams and employees alike. We’re creating tools that promote autonomy, foster trust, and let businesses focus on what truly matters.</p> <p>Our culture is built on transparency, collaboration, and a deep commitment to innovation – which is reflected in our spending solution. At Pleo, you’ll join a passionate team shaping the future of work, all while having some fun along the way.</p> <h2><strong>About the role</strong></h2> <p>We're looking for a <strong>Senior Software Engineer</strong> to join our <strong>Authentication &amp; Authorization team</strong> at Pleo. In this role, you'll help build and evolve secure, scalable systems that handle authentication and authorization across our platform. You'll be part of a brand-new team responsible for renewing our approach to identity, access, and trust as we scale our product.</p> <p>If you're excited about tackling complex technical challenges, collaborating across teams, and making authentication surprisingly easy for developers, this is the opportunity for you!</p> <h2><strong>What you’ll be doing</strong></h2> <p>As a <strong>Senior Software Engineer</strong>, you will:</p> <ul> <li><strong>Design and deliver</strong> robust, scalable components of our authentication and authorization systems<br/><br/></li> <li><strong>Collaborate</strong> with product, platform, and security teams to align solutions with business and infrastructure needs<br/><br/></li> <li><strong>Drive quality</strong> through best practices in testing, observability, and operational excellence<br/><br/></li> <li><strong>Mentor and guide</strong> junior engineers, fostering a culture of learning and curiosity<br/><br/></li> <li><strong>Influence technical direction</strong>, contributing to design decisions that balance security, performance, and developer experience<br/><br/></li> </ul> <h2><strong>What you bring</strong></h2> <p>You’ll thrive in this role if you have:</p> <ul> <li><strong>Deep technical expertise</strong> in building scalable systems and APIs<br/><br/></li> <li><strong>Strong collaboration and communication skills</strong>, especially when working cross-functionally<br/><br/></li> <li><strong>A passion for problem-solving</strong>, particularly in identity and access domains<br/><br/></li> <li><strong>A proactive mindset</strong>, with the ability to navigate ambiguity and drive clarity<br/><br/></li> <li>Experience with <strong>cloud infrastructure</strong> (AWS or GCP), Kubernetes, and distributed systems<br/><br/></li> <li>Experience working with <strong>authentication and authorization standards</strong> (OAuth, OIDC, etc.)<br/><br/></li> <li>A background in <strong>Kotlin, TypeScript</strong> or similar backend languages<br/><br/></li> <li>Bonus: Experience with third-party auth providers like Auth0 or AWS Cognito<br/><br/></li> </ul> <h2><strong>Who you’ll be working with and reporting to</strong></h2> <p>You’ll work closely with teams in <strong>Product Engineering, Backend Core, and Security</strong>. Our team of <strong>authentication-focused engineers</strong> is highly collaborative and dedicated to building foundational systems that keep Pleo secure and flexible. You’ll also partner with teams across <strong>Infrastructure and Developer Experience</strong> to drive adoption and impact.</p> <h2><strong>How you’ll develop in this role</strong></h2> <p>In your first 6 months at Pleo, you’ll:</p> <ul> <li>Lead the delivery of key authentication components that enable secure and seamless user and service interactions<br/><br/></li> <li>Collaborate with platform teams to improve our internal developer experience with authentication<br/><br/></li> <li>Grow your skills in platform architecture, security engineering, and cross-team influence<br/>We’re committed to helping you develop your career, whether that means taking on bigger projects, stepping into leadership, or acquiring new skills in distributed systems or security engineering.<br/><br/></li> </ul> <h2><strong>Salary Range</strong></h2> <p>The annual salary for this position varies based on your location:<br/><strong>United Kingdom:</strong> up to £86,500<br/><strong>Spain/Portugal</strong>: up to €92,500<br/><br/>We’re happy to share more about our approach to pay and this range during your first call with us!</p> <h2><strong>Show me the benefits!</strong></h2> <ul> <li>Your own Pleo card (no more out-of-pocket spending!)<br/><br/></li> <li>Lunch is on us for your work days – enjoy catered meals or receive a lunch allowance based on your local office 🍜<br/><br/></li> <li>Comprehensive private healthcare – depending on your location, coverage options include Vitality, Alan or Médis<br/><br/></li> <li>We offer 25 day