Backend Developer (VoIP)

Senior Backend Developer

Alohi

Alohi is an AI-first SaaS scale-up on a mission to simplify how businesses work. Our products (Sign.Plus, Dial.Plus, Fax.Plus, and Scan.Plus) serve 5M+ customers worldwide, from small businesses to global enterprises. We're building category-defining tools that people actually love to use. We started with seed support from FONGIT (Fondation Genevoise pour l'Innovation Technologique), backed by the State of Geneva. Since then, we've chosen to bootstrap our growth. This keeps us financially independent, customer-focused, and able to move fast without external constraints. We're a lean, fast-growing team based in Geneva with strong traction across global markets. This is an entrepreneurial environment where you'll have high ownership, broad responsibilities, and direct impact from day one. If you want to build something meaningful in a fast-paced, innovation-driven company, without the chaos of early-stage uncertainty or the bureaucracy of a large corporation, this is it. We are hiring a Senior Backend Developer to build and scale the server-side systems that power our products. You'll own the development of APIs, backend modules, and database architecture, ensuring high performance and reliability as we serve millions of users worldwide. This position is fully on-site at our Geneva office. RESPONSIBILITIES We're looking for a hands-on engineer who can design, build, and maintain backend systems that scale. Backend Development * Build and maintain mission-critical backend systems to support high-volume requests across our product suite * Design and develop robust APIs and web services that power our frontend applications * Develop and maintain backend modules, ensuring clean architecture and maintainable code * Build backend infrastructure for AI-powered features, including integration with LLMs, model APIs, and data pipelines for machine learning workflows Performance & Scalability * Identify and resolve performance bottlenecks in a high-traffic, scalable environment * Optimise database queries and system architecture to handle growing demand * Ensure development tasks are completed within timelines with minimal defects Infrastructure & DevOps * Work with containerisation technologies (Docker, Kubernetes) to deploy and manage services * Contribute to CI/CD pipelines and build systems to streamline development workflows * Participate in on-call rotations to ensure system reliability and respond to production incidents * Collaborate with cross-functional teams to deliver features end-to-end REQUIREMENTS * 3–5 years of experience in backend software engineering, ideally in a technology-driven or SaaS environment * Strong proficiency in Python * Solid experience with complex data structures and databases (MongoDB, MariaDB, Elasticsearch) * Able to critically evaluate and effectively use AI-assisted development tools while maintaining a deep understanding of the underlying code * Strong Linux knowledge and hands-on experience * Good understanding of HTTP, REST, web servers, and microservices architecture * Experience with containerisation (Docker, Kubernetes) * Familiarity with build systems and CI/CD procedures * Ability to write clean, scalable, and well-tested code * Strong problem-solving skills and attention to detail * Fluent in English (written and spoken) WHAT WE OFFER Office First: We believe the best collaboration happens in person. You'll be based at our Geneva office, working alongside a lean, high-calibre team where ideas flow freely and decisions happen fast. AI-First Technology: We provide all the devices and software you need to excel, including access to cutting-edge AI tools and a modern tech stack. You'll have the best resources at your disposal to move quickly and build great things. Personal Development: We invest in your growth with a dedicated learning budget for training programmes, conferences, courses, and professional development opportunities. Quarterly Events & Annual Retreats: Regular team events and company-wide retreats to connect, celebrate wins, and have fun together. Award-Winning Culture: We're proud to be recognised as a Great Place to Work and Best Workplace, reflecting our commitment to building an environment where talented people thrive. Perks & Wellbeing: Weekly yoga sessions, plus discounts on gym memberships, restaurants, and Apple products to support your lifestyle inside and outside of work.

Engineering Manager (Apple) - Geneva

Proton

Join Proton and build a better internet where privacy is the default Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives! We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 700+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here! Purpose of the role:  As the Engineering Manager for Proton VPN, for the iOS and MacOS team, you lead a team of engineers dedicated to fostering continuous innovation in our applications. Reporting to the Engineering Manager, you will collaborate with cross-functional teams across Proton. Your primary objective is to raise the quality and reliability of our Apple platform products, while ensure Proton VPN keep being extended with new and critical functionalities. Responsibilities include:  * Raise and maintain a high engineering bar for iOS and macOS VPN products by diagnosing quality issues, implementing clear processes, and ensuring delivery of robust, reliable features. * Enhance team efficiency by balancing speed, quality, and developer experience through streamlined processes and structured ways of working. * Collaborate closely with Product to address quality concerns while delivering on the roadmap. * Strategically analyse engineering challenges and guide the team in breaking them down into manageable, iterative solutions—adjusting scopes to meet goals quickly without sacrificing quality. * Ensure transparent communication of priorities, context, and technical decisions within the team and across stakeholders. * Foster team growth through personalised 1-on-1s, performance evaluations, and career development plans. * Oversee cross-team projects with R&D, Backend, Infrastructure, QA, and Product to ensure seamless coordination and execution * Influence and collaborate with internal teams and stakeholders to align engineering efforts with business objectives and Proton’s security mission. Job requirements: * Experience managing Mobile teams, delivering Mobile products and navigating complex cross-team efforts. * Proven track record of improving product quality and implementing processes in a fast-moving environment. * Experience leading or contributing to release processes and delivering software at scale, ideally in networking, VPN, or other performance-critical domains. * Strong understanding of mobile-specific engineering challenges and the ability to go deep technically when diagnosing issues. * Skilled in project management—able to keep initiatives moving, align stakeholders, and ship high-quality releases. * Clear, concise, and impactful communication skills. * Comprehensive understanding of the full application lifecycle, from code reviews and CI/CD to deployment and post-release troubleshooting. * Familiarity with low-level networking concepts (VPN protocols, DNS, TCP/IP) is beneficial. * Passion for creating an environment where teams are motivated, collaborative, and focused on delivering exceptional user experiences. 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. Depending on the role, fully remote positions may also be available. * 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

Full Stack Engineer

Sonar

Who is Sonar?   Sonar is driving the future of agent-centric software development. As the leader in AI code review and verification, we solve a critical problem: ensuring that software generated by AI-assisted developers or autonomous agents is reliable, secure, and maintainable. Integrating seamlessly with Claude Code, Codex, Cursor, GitHub Copilot, Gemini, and Devin, we help over 75% of the Fortune 100 build trusted, reliable, compliant software. Customers who use Sonar are 44% less likely to report an outage due to AI-generated code. We believe code verification is the critical missing link in the Agent-Centric Development Cycle (AC/DC). Industry giants like Nvidia, ServiceNow, Booking.com, Goldman Sachs, AstraZeneca, and Ford Motor Company.count on us to provide independent, explainable, consistent review and governance of their AI-generated code via products like: SonarQube: The world’s leading AI code review and verification platform. SonarQube Foundation Agent: Currently topping the leaderboards for agentic software repair. SonarSweep & Sonar Context Augmentation: Providing the enterprise-grade context and constraints agents need to be truly effective. Our team operates across global hubs in Austin, Bochum, Dubai, Geneva, London, Singapore, Tokyo, and Washington D.C. We move with a mindset we call CODE: Committed to our customers and community. Obsessed with quality. Deliberate in our decisions. Effective as one team. With over $400M in revenue and profitable, fast-paced growth, we are building the backbone of the AI software revolution. If you’re hungry to have an impact, want to build at a fast pace, and ready to work at the forefront of AI, we want to hear from you.   Position description   Our website is the front door to the Sonar ecosystem. It is where developers and organizations discover our products, and where our marketing and data systems connect to the outside world. You will work across both sides of that: building the UI people see and the integrations they do not. You will start by contributing across the full stack and progressively own entire domains end-to-end: UI delivery: Build accessible, performant components from design specs for a growing number of websites that serve a global audience across 7 languages. Analytics & tracking: Own how we instrument the websites (event tracking, data layer, tag management) so that marketing and product teams can measure what matters. Marketing integrations: Own the backend connections between our frontend and our business systems (forms, lead capture, automation workflows) ensuring data flows accurately from the browser to internal tools. We have built our development workflow around AI-assisted coding and we expect you to push that further. AI handles more of the repetitive work over time, which means your role expands into higher-impact territory, not less.