
Spotify · Stockholm
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 Authoriza...
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.
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.
We're looking for a Senior Product Manager to lead the strategy and evolution of Encore, Spotify's design system. In this role, you'll define the vision and roadmap for the design infrastructure that powers product development across the company. You'll work at the intersection of design, engineering, accessibility, and artificial intelligence, ensuring that our systems are built not only for the people using them today, but also for the AI-assisted workflows shaping how software will be built tomorrow. This is a senior individual contributor role requiring strategic thinking, strong product judgment, and the ability to lead complex cross-functional initiatives through influence. You'll partner closely with engineering, design, research, and leadership to align priorities, make thoughtful trade-offs, and drive measurable outcomes across Spotify's product ecosystem.
Join Proton and build a better internet where privacy is the default At Proton, we believe that privacy is a fundamental human right and the cornerstone of democracy. Since our inception in 2014, founded by a team of scientists from CERN, we have dedicated ourselves to providing free and open-source technology to millions worldwide, ensuring access to privacy, security, and freedom online. Our journey began with Proton Mail, the largest secure email service globally, and has since expanded to include Proton VPN, Proton Calendar, Proton Drive, and Proton Pass. These tools empower individuals and organizations to take control of their personal data, break away from Big Tech’s invasive practices, and defeat censorship. Our work impacts hundreds of millions of lives, from activists on the front lines defending freedom to leaders in governments protecting sensitive information. In some cases, Proton’s services have even been instrumental in saving lives by enabling secure and private communications in high-risk situations. Proton is a profitable company that does not rely upon VC funding, supporting over 100 million user accounts with a growing team of over 500 people from over 50 different countries, from the world's top companies and universities. We value intelligence, learning potential, and ambition in our hiring process. Adaptability is key as we navigate uncharted territories and redefine how business is conducted online. Hiring at Proton is highly selective, with less than 1% of candidates hired. We believe smaller teams of exceptional talent will always prevail over larger teams with lower talent density. You will have the opportunity to work with many of the world's top minds in their fields, ranging from former international math and science olympiad winners to chess champions. We have a global mindset and big ambitions but remain a start-up at heart. We value empowerment and flexibility and keep our structure flat to keep moving fast and avoid unnecessary politics. Tired of blending into the crowd? Join us and do work you can truly be proud of. Check our open-source projects here! The team: Proton VPN enables millions of people to connect securely and privately, even in places where the internet is restricted or unreliable. Delivering that experience means our service must perform flawlessly under highly variable, real-world conditions. We are looking for a Senior Performance Engineer to lead our efforts in making Proton VPN the fastest, most resilient, and most reliable VPN service in the world. You will define and drive the measurement, analysis, and optimization of Proton VPN’s end-to-end performance, across clients, platforms, and global infrastructure. You’ll help ensure that every connection is fast, stable, and private, regardless of where the user is or what network they’re on. What you will do: * Design and own Proton VPN’s performance framework, defining metrics and KPIs that reflect the real-world experience of users (time-to-connect, throughput, latency, stability, reconnection rates, etc.). * Develop distributed testing systems that simulate real network conditions, including low bandwidth, packet loss, and high-latency scenarios. * Continuously measure and analyze performance across platforms (desktop, mobile, backend) and regions to identify bottlenecks and regressions. * Collaborate with backend, R&D, and client teams to optimize protocol handling, connection setup, routing, and encryption performance. * Create dashboards, reports, and automated alerts to track global performance health. * Contribute to the design of resilient connectivity strategies that adapt dynamically to variable network conditions. * Serve as the performance champion within the engineering organization, mentoring others and driving a data-driven performance culture. Job requirements: Technical Skills * 5+ years of experience in performance engineering or systems QA, ideally in networking, VPNs, or distributed systems. * Knowledge of network protocols (TCP/IP, UDP, TLS, WireGuard, debugging, manipulating, and performance profiling tools. * Proven ability to analyze latency, throughput, and stability metrics across multiple layers (client, OS, transport, application). * Proficiency in Python (or similar scripting language) * Familiarity with network emulation and simulation tools (e.g., tc/netem, iperf, IPTables/nfTables…). * Experience with monitoring and observability stacks (Grafana, Prometheus, Loki) and CI/CD pipelines. * Cross-platform experience with Linux, macOS, Windows, Android, and iOS preferred. Bonus points for: * Experience with Rust/C/C++/System development Soft Skills * Analytical and methodical, yet creative in solving complex performance problems. * Comfortable working with uncertainty and non-deterministic conditions. * Collaborative mindset, able to work across client, infrastructure, and data teams. * Strong communication and documentation skills in English. What We Offer * Office First: Collaboration is easier and more effective in person, which is why we have offices in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje, and Taipei. You can also enjoy working from home up to 30% of the time, while enjoying great company during our three core days in the office. * Technology: We provide all the devices and software you need to excel in your role, ensuring you have the best tools at your disposal to achieve your goals. * Food: Lunch and snacks are provided by Proton every day at our offices. * Transport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location. * Stock Options: At Proton, we are all owners of the company and you get stock options when you join us. * Flexible Working: You can define your own working hours as long as it works with team meetings. * Learning and Development: We are committed to your professional growth. Proton offers various learning opportunities, including training programs, conferences and events, and continual learning. * Employee Benefits: Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs. * Work that Matters: Proton is a community-first organization, started with the support of a crowdfunding campaign and built with community input. To this day, Proton’s only source of revenue is user subscriptions. Over 100 million people trust and support Proton, and we put our users and community first in everything we do. Read more about our impact here. Our Commitment to Diversity and Inclusion At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected. If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know. Candidate Privacy Notice When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills. If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch. Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton. To learn more about our privacy policy, please visit our privacy policy page. #LI-Onsite
WorkNomads is seeking a Software R&D Team Lead to join our diverse team, working remotely from the EU or from the WorkNomads base in Sofia, Bulgaria. The Software R&D Team Lead is responsible for leading and developing a team of software engineers working on specialized software development, including AI-integrated neurotech, industrial, and mobile applications systems. Success in this role requires exceptional communication skills, the ability to make informed decisions under uncertainty, and a strong sense of ownership. You will collaborate with product, design, and operations teams, challenge assumptions constructively, and support the engineering organization in delivering sustainable value over time. Key Duties and Responsibilities: • Lead, grow and develop a team of software engineers working on specialized software development, including AI-integrated neurotech, industrial, and mobile applications systems. • Build strong observability, incident management, and release pipelines to maintain high service availability and velocity. • Get hands-on contributing to software design, architecture, implementation and testing • Provide technical leadership to the team members. • Represent the team during collaboration with other cross-functional teams. • Support the performance goals definition, their monitoring and execution. • Set the technical roadmap, choose the right tech stack, align engineering goals with our overarching business objectives and manage it Requirements The tools in your backpack: • 10+ years experience in software engineering with at least 3 years in senior technical leadership role. • Demonstrated ability to build and lead high-performing engineering teams • Proficiency and/or high experience with C#, C++, Python • Experience with mobile development platforms (iOS, Android, Flutter) • Proficiency in API design, microservices, and data security • Extensive experience with proven track record of leading technology teams in software product development • Strong understanding of AI technologies and ability to integrate AI/ML • Deep understanding of CI/CD pipelines, testing frameworks, observability • Expert knowledge of general software engineering concepts, e.g. design patterns, algorithms, and data structures. • University degree in the field of computer science, applied mathematics, electronic engineering or comparable qualifications. • Fluent written and spoken English (C1 level). Other nice-to-have tools: • Familiar with neuroscience, industrial communication and voice-driven user interaction technologies is a plus • Familiar with cloud-native driven services using Kubernetes, Terraform or similar technology is a plus • Experience with cloud platforms such as AWS, Google Cloud, or Azure and DevOps practices is a plus Benefits Perks of being one of us: Flexible work setup: work fully remotely from any country in the EU on a freelance/B2B contract, or join our Sofia, Bulgaria office under a local employment contract that offers a comprehensive social welfare package. Autonomy: an environment where your technical vision matters, and you own your work-life balance. Growth: a personalized career development program to fuel your journey; learn from experts, expand your craft, and work across industries. Global vibe: an international, dynamic, remote-first workplace. Connectivity Support: coverage for internet and phone bills (50 EUR gross). Total Rewards: paid time off and competitive remuneration. Community: team get-togethers and networking events are in our DNA! Seamless Living: need a base? Digitally check into a spacious room at our WN LAB Hotel, Bulgaria’s biggest and coolest 4★ co-living hotel. No deposit, with special discounted rates for single apartments starting from 660 EUR/month (utilities & cleaning included!). Be part of something beyond work: culture, values, impact. How to Apply / What Happens Next: 1. Send us your CV by hitting the “Apply” button. 2. You will hear from one of our Global Talent Connectors within 5 business days with the next steps. 3. Meet us on MS Teams and tell us what excites you. 4. Next stage could be a test or a task - we want to see what you DO (not just what you say) 5. Along this journey and depending on the role you are applying for, prepare to meet either our Chief Talent Gaucho, your future leader or our Head Honcho!