Software Engineer (Cross-Platform Applications)

Meet Yubico Yubico is a global leader in identity security and creator of the YubiKey, the original hardware-backed passkey. We are publicly traded on Nasdaq Stockholm; our global footprint includes headquarters in Stockholm, Sweden, Silicon Valley, California; and Singapore. Why Join Our Mission? At Yubico, we are guided by a shared belief that your work matters. We operate under a cultural philosophy of Speed with Integrity , pushing the boundaries of technology to secure the AI frontier—protecting both human and agentic AI interactions—and leading the transition to post-quantum cryptography. In everything we do, we live by our core values: • Battle Friction: We constantly look for new ways to simplify our products, our work, and the user experience. • Inspire Higher: We think big, champion the open internet, and strive to do the right thing even when it is difficult. • One Team: We are open, responsive, and collaborative, overcoming challenges and celebrating our successes together. Aligned with our commitment to open standards, we foster a thriving builder ecosystem through the Yubico Developer Program , offering free open-source repositories , libraries, and SDKs to help developers rapidly integrate strong hardware authentication into any application. Through close collaborations with technical partners like Google, Microsoft, and Amazon, as well as newer frontiers like OpenAI, we continue to shape a safer digital world while donating security keys to protect vulnerable communities, journalists, and humanitarian groups worldwide through our Secure it Forward program. The Role We are looking for a versatile Software Engineer to join our Stockholm-based team to help shape the future of Yubico’s software products. In this role, you will focus on building high-quality, secure applications across desktop and mobile platforms using Flutter, while also contributing to our command-line tools and libraries. As part of our team, you will play a key role in refining our cross-platform strategy. While our team includes iOS and Android experts to address platform-specific requirements, we look for a generalist who won’t shy away from working in these environments. You should be eager to explore new technologies and take full ownership of your work. We encourage you to use the best tools for the job, including AI. Ultimately, you are accountable for the quality, security, and performance of the code you ship. Tasks & Responsibilities: • Develop, test, and maintain cross-platform graphical applications using Flutter for Desktop and Mobile. • Contribute to the development and maintenance of CLI tools and libraries alongside graphical applications. • Take end-to-end ownership of features, from initial design through to packaging and deployment. • Collaborate with UX/UI designers to implement intuitive and beautiful user interfaces. • Ensure code quality through rigorous testing and maintain full accountability for all code you ship, regardless of how it was created. Basic Qualifications: • Bachelor or MS in Computer Science, a relevant technical discipline, or equivalent work experience • Strong programming fundamentals and experience with at least one modern UI framework • Experience building mobile (iOS/Android) and/or desktop (Windows/macOS/Linux) applications • A versatile mindset with the ability to learn and adapt to new technologies (like Dart/Flutter or Rust) quickly. • Ability to write secure, testable, and maintainable code • Self-motivated with a high degree of autonomy and the ability to take full ownership of the codebase Bonus Qualifications: • Experience with Flutter development in a production environment • Experience with cryptography (PKI, digital signatures, etc) • Experience with CI/CD pipelines (