Why This Job is Featured on The SaaS Jobs
This Senior C++ and iOS role sits in a core identity layer that many SaaS platforms depend on but rarely expose: session management and delegated authorization. By operating in OAuth 2.0 infrastructure and token lifecycle domains, the work connects product surfaces, partner integrations, and platform reliability, which are central concerns for subscription software at scale. The remit also reflects a mature SaaS environment where internal platforms enable many downstream teams and external developers.
For a SaaS career, the standout value is depth in security sensitive platform engineering that transfers across industries and product categories. Experience building shared C++ libraries alongside native Swift, and coordinating client and backend integration points, maps directly to how modern SaaS organisations standardise authentication, reduce duplication across apps, and evolve protocols without breaking consumers. It also builds credibility in risk aware engineering where correctness, observability, and long term maintainability matter as much as feature delivery.
The role best suits engineers who enjoy cross boundary systems work, from on device credential handling to service level token issuance. It will appeal to those comfortable influencing technical direction, collaborating across multiple teams, and working in domains where careful design decisions create leverage for many other engineers.
The section above is editorial commentary from The SaaS Jobs, provided to help SaaS professionals understand the role in a broader industry context.
Job Description
We’re looking for a Senior C++/iOS Engineer to join the Baldur squad within User Platform (UP). Baldur owns Spotify’s Session Management and Delegated Authorization domains—the systems that enable applications to securely obtain, use, and manage access tokens for hundreds of millions of users. In this role, you’ll help shape the technology that powers secure access across every Spotify client and third-party integration through our OAuth 2.0 infrastructure.
Your work will support engineers across Spotify building mobile and desktop experiences, platform teams, and third-party developers integrating with Spotify’s authorization platform. You’ll collaborate across disciplines to build secure, reliable, and scalable authentication experiences that have a direct impact on millions of people every day.
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What You'll Do
- Collaborate with a highly autonomous and supportive engineering squad responsible for Spotify’s delegated authorization and session management platforms.
- Design, build, and evolve critical infrastructure powering Spotify applications and partner integrations using shared C++ libraries and native Swift on iOS.
- Develop secure, reliable, and performant delegated authorization flows, including token issuance, refresh, revocation, and session lifecycle management across multiple platforms.
- Partner with client and backend engineers to integrate with core authorization services, including Keymaster for OAuth token issuance, client registration, and token revocation.
- Improve how credentials and access tokens are securely stored and managed on-device while balancing security, reliability, and application performance.
- Contribute to the evolution of Spotify’s authorization frameworks, including OAuth 2.0 and Spotify-specific implementations, enabling new platforms and product experiences.
- Drive technical improvements, share knowledge with teammates, and help shape the long-term technical direction of delegated authorization and session management.
Who You Are
- You have strong proficiency in C++, along with experience building native iOS applications in Swift, or you're excited to develop your expertise in Swift while applying your C++ skills.
- You have experience designing, building, or maintaining security-sensitive systems such as authorization, authentication, token management, credential storage, or related platforms.
- You bring a systems-thinking mindset and enjoy solving complex engineering challenges that span client and backend technologies.
- You have a solid understanding of software architecture, secure system design, and modern authorization protocols such as OAuth 2.0.
- You approach problems thoughtfully, with strong attention to detail and a focus on building secure, reliable, and maintainable solutions.
- You communicate clearly and enjoy collaborating with engineers across multiple teams and technical disciplines.
- You have experience working with shared cross-platform codebases and understand how native platform layers interact with common C++ libraries.
- You enjoy working on large-scale distributed systems where your contributions improve experiences for hundreds of millions of Spotify users.
Where You'll Be
- This role is based in London or Stockholm.
- We offer you the flexibility to work where you work best! There will be some in person meetings, but still allows for flexibility to work from home.
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Spotify is an equal opportunity employer. You are welcome at Spotify for who you are, no matter where you come from, what you look like, or what’s playing in your headphones. Our platform is for everyone, and so is our workplace. The more voices we have represented and amplified in our business, the more we will all thrive, contribute, and be forward-thinking! So bring us your personal experience, your perspectives, and your background. It’s in our differences that we will find the power to keep revolutionizing the way the world listens.
At Spotify, we are passionate about inclusivity and making sure our entire recruitment process is accessible to everyone. We have ways to request reasonable accommodations during the interview process and help assist in what you need. If you need accommodations at any stage of the application or interview process, please let us know - we’re here to support you in any way we can.
