ph3Senior Performance Engineer /h3 pWe 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. /p h3What you will do /h3 ul liDesign 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.). /li liDevelop distributed testing systems that simulate real network conditions, including low bandwidth, packet loss, and high-latency scenarios. /li liContinuously measure and analyze performance across platforms (desktop, mobile, backend) and regions to identify bottlenecks and regressions. /li liCollaborate with backend, RD, and client teams to optimize protocol handling, connection setup, routing, and encryption performance. /li liCreate dashboards, reports, and automated alerts to track general performance health. /li liContribute to the design of resilient connectivity strategies that adapt dynamically to variable network conditions. /li liServe as the performance champion within the engineering organization, mentoring others and driving a data-driven performance culture. /li /ul h3Job requirements /h3 h3Technical Skills /h3 ul li5+ years of experience in performance engineering or systems QA, ideally in networking, VPNs, or distributed systems. /li liKnowledge of network protocols (TCP/IP, UDP, TLS, WireGuard, debugging, manipulating, and performance profiling tools.). /li liProven ability to analyze latency, throughput, and stability metrics across multiple layers (client, OS, transport, application). /li liProficiency in Python (or similar scripting language). /li liFamiliarity with network emulation and simulation tools (e.g., tc/netem, iperf, IPTables/nfTables…). /li liExperience with monitoring and observability stacks (Grafana, Prometheus, Loki) and CI/CD pipelines. /li liCross-platform experience with Linux, macOS, Windows, Android, and iOS preferred. /li /ul h3Bonus points for /h3 ul liExperience with Rust/C/C++/System development.



/li /ul h3Soft Skills /h3 ul liAnalytical and methodical, yet creative in solving complex performance problems. /li liComfortable working with uncertainty and non-deterministic conditions. /li liCollaborative mindset, able to work across client, infrastructure, and data teams. /li liStrong communication and documentation skills in English. /li /ul h3What We Offer /h3 ul liOffice 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. /li liTechnology: 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. /li liFood: Lunch and snacks are provided by Proton every day at our offices. /li liTransport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location. /li liStock Options: At Proton, we are all owners of the company and you get stock options when you join us. /li liFlexible Working: You can define your own working hours as long as it works with team meetings. /li liLearning and Development: We are committed to your professional growth. Proton offers various learning opportunities, including training programs, conferences and events, and continual learning. /li liEmployee Benefits: Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs. /li liWork 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. /li /ul h3Our Commitment to Diversity and Inclusion /h3 pAt 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. /p pIf you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know. /p h3Candidate Privacy Notice /h3 pWhen 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. /p pIf 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 /p pProton 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. /p pTo learn more about our privacy policy, please visit our privacy policy page. /p /p #J-18808-Ljbffr

📌 Senior R&D Engineer (Barcelona)
🏢 proton tehnologies
📍 Barcelona