
Proton · Barcelona; London
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 fundame...
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 500+ 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!
The Payments Team
The goal of the Payments team is to enable revenue generation for the entire Proton ecosystem. This comes in the form of
introducing new payment methods for users to architecting our client libraries. This team has impact across all of Proton's
products and is critical to the success of the business as a whole.
payment methods, beyond just plain credit cards or Paypal.
team, and every single Business Unit to ensure that plans, promotions and pricing meet user expectations.
building enticing interfaces, being able to progressively reach global markets, by providing the methods and tooling allowing
users to pay, and for the Proton organization to properly being able to measure growth, and to follow the relative financial
regulations
providers, tax-information providers, currency-conversion providers... As such it is critical, for the success of the service,
to build with resilience.
Kotlin (on Android) and on Swift (on iOS), with a growing shared codebase in Rust.
breadth of topics ranging from demystifying payment performance data across regions/products, to thinking about the holistic
strategy of product catalogs, and everything in between. This particular team requires someone who is a strong generalist, who
thrives with ambiguity. There's huge potential for growth no matter the domain, and the outcome for any candidate is an
in-depth view into how money moves globally.
Even if you don’t meet all the requirements listed above, but feel you could still be a great fit, please still apply.
What We Offer
investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more
about our impact here)
life, including many of the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech,
Cambridge, and ETH.
accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
leave, and wellness support so you can bring your best self to work every day
we're building. When Proton wins, you win.
With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with
people who genuinely care about what they're building
for you.
clock says you started.
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.
This is Adyen Adyen provides payments, data, and financial products in a single solution for customers like Meta, Uber, H&M, and Microsoft - making us the financial technology platform of choice. At Adyen, everything we do is engineered for ambition. For our teams, we create an environment with opportunities for our people to succeed, backed by the culture and support to ensure they are enabled to truly own their careers. We are motivated individuals who tackle unique technical challenges at scale and solve them as a team. Together, we deliver innovative and ethical solutions that help businesses achieve their ambitions faster. About the Team The Payment Gateways team (used to be known as IPP Payments Backend) is a critical pillar of Adyen’s Core Payments solution. The Core Payments group handles the foundational business logic, diverse payment flows, and global features that empower Adyen’s merchants worldwide. As part of the Payment Gateways team, you will design and build the infrastructure powering Adyen’s in-store payment experience. This means engineering systems capable of handling massive, simultaneous global traffic while maintaining rock-solid reliability for thousands of physical terminals, mobile devices, and merchant hosts. What You Will Do As a Backend Engineer (Java), you will orchestrate complex payment flows by integrating multiple Adyen systems and defining the unified architecture for our next-generation payment features. * Design & Deliver: Build, test, and deploy high-volume, low-latency Java applications that form the backbone of our global payment systems. * Architect for Scale: Collaborate across Data and Platform engineering teams to design highly resilient, scalable services with reliability at their core. * Own the Technical Lifecycle: Drive engineering best practices, contribute to scalable architecture designs, and actively participate in product roadmap discussions. * Data-Driven Optimization: Define, implement, and monitor performance KPIs to proactively identify and eliminate system bottlenecks. * Collaborate Globally: Partner cross-functionally with global product managers and engineers, occasionally collaborating directly with merchants to understand how businesses consume your solutions. Who You Are * Senior Java Developer: You have 8+ years of hands-on experience delivering high-impact backend services using Core Java, web services, and SQL/PostgreSQL, with a proven track record of technical leadership and mentoring junior engineers. * Scalability: High availability, fault tolerance, and low latency aren't afterthoughts for you—they are non-negotiable architectural prerequisites. * API Expert: You possess a strong understanding of modern API frameworks (such as REST and OpenAPI), alongside best practices for API security and developer experience. * Curious & Forward-Thinking: You actively evaluate emerging technologies and alternatives, confidently presenting your findings during architectural reviews. * Collaborative Communicator: You know how to get things done by actively seeking out diverse perspectives and bringing people together to solve complex problems. * Customer-Centric: You balance deep technical rigor with genuine Customer Empathy, always keeping the end-merchant's business success in mind. Our Diversity, Equity and Inclusion commitments Our unique approach is a product of our diverse perspectives. This diversity of backgrounds and cultures is essential in helping us maintain our momentum. Our business and technical challenges are unique, and we need as many different voices as possible to join us in solving them - voices like yours. No matter who you are or where you’re from, we welcome you to be your true self at Adyen. Studies show that women and members of underrepresented communities apply for jobs only if they meet 100% of the qualifications. Does this sound like you? If so, Adyen encourages you to reconsider and apply. We look forward to your application! What’s next? Ensuring a smooth and enjoyable candidate experience is critical for us. We aim to get back to you regarding your application within 5 business days. Our interview process tends to take about 4 weeks to complete, but may fluctuate depending on the role. Learn more about our hiring process here. Don’t be afraid to let us know if you need more flexibility. Adyen is an equal opportunity employer. We do not discriminate based on race, color, ethnicity, ancestry, national origin, religion, sex, gender, gender identity, gender expression, sexual orientation, age, disability, veteran status, genetic information, marital status or any legally protected status. All your information will be kept confidential according to EEO guidelines. This role is based out of our Bengaluru office. We are an office-first company and value in-person collaboration; we do not offer remote-only roles.
Hi! We are AMBOSS and we are looking for a Senior Backend Engineer who is passionate about robust system architecture but also eager and willing to dive into the frontend when needed. Join our team and shape the future of medical education with us! About AMBOSS AMBOSS is a dynamic learning and clinical decision support tool committed to empowering medical professionals globally to deliver optimal care. Since our inception in 2012, we've harnessed cutting-edge technology to transform the way physicians acquire and apply scientific knowledge. Each AMBOSSian is passionate about being the champion of clinicians today - this motivates and unites us each day towards success. And what does success look like? When a clinician or med student tells us, “AMBOSS makes practicing medicine easier and enjoyable. I love what I do, and a big part is because of AMBOSS.” Want to learn more about our culture? Watch our video to explore what makes us unique. Why can this position be exciting for you? As a Senior Backend Engineer in the Shop Team, you will sit at the heart of our mission, building and scaling the gateway that allows medical students and clinicians around the world to access the AMBOSS platform. In this team, your backend architectural decisions have a direct, measurable impact on revenue and user discovery. Whether you are scaling high-availability payment services or prototyping a bold new hypothesis, you will be defining how the world buys AMBOSS. While your primary expertise and core focus will be on the backend, you will also have the opportunity to expand your skill set and collaborate on our frontend application, bringing a willingness to learn and work across the full stack. You will: * Ramp Up: Become a domain expert in AMBOSS's shop and payment architecture, from deep subscription logic to international tax compliance. * Build & Scale: Design, evolve, and maintain high-availability backend services handling global payment processing and complex financial transactions. * Own the Lifecycle: Manage backend discovery, technical design, deployment, monitoring, and database management at scale. * Collaborate & Learn: Build deep working relationships with Product, Design, and Finance stakeholders. Work closely with frontend engineers and proactively learn/contribute to our React-based customer-facing application when features require end-to-end implementation. * Ship Impact: Deliver end-to-end features and backend improvements from discovery to deployment, ensuring a localized, frictionless checkout experience for our global users. * Innovate with AI: Use tools like Cursor or Copilot and research how emerging technologies (LLMs, automation) can add genuine user value. You Bring: * Go (Golang): Deep, senior-level backend fundamentals (concurrency patterns, performance tuning, robust API design, and error handling). * Frontend Willingness to Learn: A foundational understanding of modern JavaScript/TypeScript and web mechanics, paired with an open, enthusiastic mindset to learn, read, and write frontend code in React alongside our team. * API Design: Comprehensive experience building scalable, clean APIs with GraphQL and/or REST. * Architectural Intuition: The ability to deconstruct complex, monolithic codebases and design highly resilient, distributed data models at scale. * Ops & Observability: Hands-on experience with Docker, CI/CD pipelines, and cloud infrastructure (AWS/Kubernetes). You write comprehensive backend tests and aggressively monitor your own metrics and dashboards. * Product-Minded & Pragmatic: You care deeply about why we build, focusing on business value and user impact over technical complexity for its own sake. You know when to ship a quick proof-of-concept and when to invest in long-term stability. * AI-Native & Comfort with Ambiguity: You are excited by AI-assisted development and can make sound technical decisions even when requirements are still evolving. Nice to Haves * Payment Systems Knowledge: Strong conceptual understanding or direct hands-on experience building, scaling, or maintaining payment flows and subscription infrastructure (e.g., Stripe, Adyen, Braintree). * PHP: Familiarity or previous engineering experience with PHP, as it helps navigate components of our ecosystem. * Exposure to Event-driven architectures, message queues (e.g., Kafka, RabbitMQ), or distributed tracing. * Previous work with LLM integration or AI-powered features. Benefits: 🌴 Rest & Time Off (30 paid vacation days, AMBOSS holiday, personal purpose day and more) 🥙Food & Office Comfort (Daily healthy breakfast & lunch by in-house chef in Berlin HQ, AMBOSS daycare, work remotely from other office spaces in Cologne, Sardinia, Cape Town) 🏃 Health, Fitness & Mobility (Urban Sports Club -M plan- , Fitbit Versa 3, Deutschland Ticket…) Check out the full list of benefits below: https://go.amboss.com/the-amboss-prescription-de We believe that diversity is a powerful driver of innovation and progress. That’s why we are committed to fostering an inclusive, respectful, and supportive environment where everyone—regardless of gender, age, ethnic or cultural background, religion, disability, sexual orientation, gender identity—is valued and given equal opportunity to thrive. We warmly welcome people of all backgrounds to help us fulfil our mission: empowering all medical professionals to provide the best possible care 🩺 Even if you don’t meet every single point in the job description, we still encourage you to apply. We’d love to hear from you!
ABOUT THE JOB Flatpay has become one of Europe's fastest-growing payment companies by helping merchants accept card payments in-store. Our Point of Sale system serves as the central engine of the business. It streamlines the merchant's entire workflow — from order taking, product and inventory management, to payment processing, reporting, and compliance. Some of the core capabilities include: * Product catalogue: Organizes how they manage their products, categories, modifiers and inventory * Order management: Basket, pricing, discounts, payments and managing tables and long-running orders among groups of customers. * Hardware integrations to barcode scanners, receipt and kitchen/bar printers and our different Mobile-, Premium- and Basic POS devices. No least manage synchronicity across multiple POS systems at shared locations in realtime. * Our reporting suite ensures cash management, end-of-day reports, various sales, turnover, staff, tax and compliance reports that enables merchants to optimize their business and comply with local tax regulations. As our merchants grow, so does the platform. Every new market introduces new payment methods, fiscal requirements and merchant needs. Every new feature increases the depth and complexity of the product. And with our customer base doubling approximately every six months, the demands on scalability, reliability and performance continue to grow. This is a hands-on engineering role with significant ownership. You'll influence technical direction, contribute to architectural decisions and solve the engineering challenges that come with building one of Europe's fastest-growing commerce platforms. WHAT YOU'LL DO As a Senior Backend Engineer, you'll contribute far beyond implementation. You'll help shape technical direction while remaining deeply involved in building products. You'll work closely with Product, Design and fellow engineers to build software that scales across all dimensions: more merchants, more markets, more capabilities and increasingly sophisticated workflows. Your responsibilities will include: * Designing, building and evolving features across our Point of Sale platform platform. * Lead feature and platform initiatives involving multiple engineers, driving delivery from discovery through production * Build APIs, services, and integrations that enable stock, order lifecycle, sales reporting & compliance reporting towards governmental standards of our markets. * Take ownership of features from design and implementation through deployment and maintenance * Drive architectural decisions and long-term technical improvements * Improve reliability, observability, performance, and security across the platform * Mentor engineers through coaching, code reviews, and knowledge sharing * Continuously improving our engineering practices, tooling and development experience * Contribute to testing, operational excellence and contribute to a collaborative team culture WHO YOU ARE We're looking for experienced engineers who enjoy solving difficult problems and helping others succeed. You likely bring: * 7+ years of professional software engineering experience * Strong experience designing and operating distributed systems * Demonstrated ability to lead technical projects involving multiple engineers and influence architectural decisions * Comfortable navigating ambiguity and helping shape new products and systems * The ability to break down complex problems into pragmatic, maintainable solutions. * Strong communication and collaboration skills * Experience building scalable backend platforms and APIs * Continuously improve CI/CD pipelines * A collaborative mindset and a willingness to challenge ideas constructively * Contribute to testing, operational excellence and contribute to a collaborative team culture * Experience within payments, fintech, e-commerce, SaaS, or high-scale transaction systems is a plus You'll be working with the following technologies; we don't expect experience with every technology listed; we're looking for engineers who can learn quickly and help us build great products. * Java, Spring Boot, JUnit * MySQL, Flyway, SQS * REST APIs * Domain Driven Design * Docker, Terraform, AWS ECS * Ports and adapters architecture WHY FLATPAY? As part of our team, you'll join 2,000+ passionate Flatpayers dedicated to shaping the future of payments. You'll help build a strategic new business area from the ground up, working on products that directly connect merchants and consumers while shaping the future of online payments at Flatpay. We offer an inclusive environment where engineers are trusted with ownership and encouraged to make an impact. Our engineering teams work together from our Copenhagen office. We believe that close collaboration, quick feedback loops, and solving problems side-by-side help us build better products, move faster, and create a stronger engineering culture. We also provide plenty of perks including free slush ice, an on-site gym, a fully equipped gamer room, and much more. If you're ready to help build and scale the future of payments, we'd love to hear from you.