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.

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.
Partner with client and backend engineers to integrate with core authorization services, 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.

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, or credential storage.
You have a solid understanding of software architecture, secure system design, and modern authorization protocols such as OAuth 2.0.
You have experience working with shared cross-platform codebases and understand how native platform layers interact with common C++ libraries.

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.

Senior C++/iOS Engineer - User Platform