Principal Backend Engineer

Join SumUp as a Backend Engineer specializing in Go within our Payments Experience team. In this role, you will be instrumental in building and optimizing backend services that power our payment solutions. You will collaborate with cross-functional teams to enhance user experience and ensure seamless transactions.

At SumUp, we champion the everyday heroes—those with the courage and determination to pursue their passions and realize their dreams.We place small business owners at the center of our mission, crafting powerful and user-friendly financial solutions designed to empower them in managing their businesses. With a founder's mentality and a collaborative, 'team-first' spirit, our diverse teams across Europe, South America, and the United States unite to ensure that small business owners can thrive in their endeavors.About the TeamThe Payments Reporting team is integral to SumUp’s financial infrastructure, developing systems that millions of merchants depend on daily to reconcile, report, and make sense of their finances. We are currently on an exciting journey to build a reporting platform that accommodates both external integrators and internal teams at scale, delivering functionalities from file-based exports to real-time API reporting. This role has emerged due to our ambitious growth outpacing the capacity of our current team of three backend engineers, and we need someone who can take significant ownership of complex backend tasks, allowing the team to accelerate critical architectural improvements.What You Will DoDevelop and maintain backend reporting features, including Payout Reports, Payment Reports, Fee Invoices, and Transaction Reports.Design and manage Reporting APIs (like Transaction History and Payout History) that cater to both external integrators and internal stakeholders.Lead the migration of core payments functionality from legacy systems, modernizing the infrastructure that supports our reporting platform.Ensure the operational health of reporting services through effective monitoring, incident response, and performance optimization.Actively engage in planning and refinement sessions, providing technical assessments and effort estimations.Mentor junior engineers through code reviews, collaborative sessions, and knowledge sharing.

SumUp’s Payments Tribe develops tools that make transactions easier for small businesses. The team in Sofia, Bulgaria, is searching for a Junior Backend Engineer with experience in Golang to help build and maintain these payment solutions. What you will do Collaborate with engineers to develop and maintain backend services using Golang Contribute to new features that support payment processing for users worldwide Assist in improving the reliability and usability of payment systems Role impact This position supports SumUp’s mission to simplify payments for small businesses and enhance the experience for users globally.

As a Payment Experience Specialist, you will become the trusted ally for our users, stepping in whenever payment issues arise. Whether a transfer is delayed or something seems amiss, you will diligently investigate with precision and care. Your mission is to ensure swift and accurate resolutions — eliminating confusion and guesswork.Embrace ResponsibilityIn this role, your responsibility extends beyond problem-solving; it involves keeping our users informed and confident throughout their journey. You will clarify the situation, outline the next steps, and indicate if any actions are required from their end. Your goal is to transform frustrating experiences into seamless interactions, making banking feel effortless.Deliver high-quality, empathetic support in every interaction, ensuring users feel heard and valued throughout their payment journey.Manage escalated payment issues by conducting thorough investigations, coordinating with relevant teams, and ensuring timely and accurate resolutions.Act promptly in urgent situations, recognizing the needs of distressed users and providing reassurance through swift action.Maintain clear communication with users by setting expectations, providing updates, and following through until their issues are fully resolved, fostering a transparent support experience.

About UsAt Redis, we are at the forefront of technology, powering the applications that millions rely on every day. Our innovative solutions streamline processes and enhance user experiences across various industries. If you've ever checked the weather, made an online payment, or tracked your flight status, you've touched our technology. Join us in our mission to create a faster, simpler world.We are seeking a talented and experienced Senior Software Engineer with a passion for polyglot programming, particularly in Go. You'll play a pivotal role in advancing the Redis ecosystem by enhancing the developer experience through collaboration with open source communities and contributing to our widely used client libraries.Why You'll Love This RoleIf you thrive in a collaborative environment and have a passion for open source, this is the perfect opportunity for you. We believe that APIs should be intuitive and delightful to work with, and you’ll have the chance to drive that vision forward. Your strong engineering mindset will help transform innovative ideas into reality as you work across multiple programming paradigms.Your ResponsibilitiesContribute to the development of key client libraries like go-redis, redis-py, predis, and node-redis.Engage with open source communities to foster collaboration and innovation.Promote best practices to ensure an exceptional developer experience.Assist in adding support for new Redis features in client libraries.Act as a technical lead on cross-language initiatives.Work closely with external contributors, library users, product managers, and fellow engineers to drive projects forward.QualificationsStrong team collaboration skills.Proficiency in multiple programming languages and paradigms.Experience with open source projects and community engagement.A passion for creating intuitive and enjoyable APIs.

Role overview SumUp is hiring a Software Engineer with solid experience in Golang to join the team in Sofia, Bulgaria. This position centers on building and maintaining online payment solutions that help businesses worldwide process transactions reliably. What you will do Design, develop, and maintain payment services using Golang Collaborate with engineering, product, and design teams Enhance existing systems to improve performance and reliability Implement new features that support user experience and system efficiency Team culture SumUp engineers work together across disciplines to deliver payment products for a global audience. The team values practical approaches and prioritizes solutions that make a real difference for users.

SumUp is hiring a Senior Software Engineer with deep Golang expertise to join the Payments Platform team in Sofia, Bulgaria. This team develops and enhances scalable payment solutions that form the foundation of SumUp’s core products. Key responsibilities Work closely with fellow engineers to design and implement features for the Payments Platform Write, review, and maintain high-quality Go code Focus on improving the platform’s performance and reliability Contribute to technical decisions that impact the future direction of payments at SumUp Requirements Professional experience working with Golang Proven background in building scalable backend systems Interest in payments technology and a commitment to platform reliability Strong collaboration and communication abilities

Join Us in Empowering Wealth CreationAt trading212, we are redefining the landscape of trading and investing by crafting innovative products that resonate with users. Our commitment to excellence and rapid execution has been pivotal to our growth.Currently, we proudly support over 4.5 million clients, managing more than €30 billion in assets—an impressive reflection of the trust and scale we’ve achieved in just a few years.Your Role and ResponsibilitiesTake a comprehensive approach to problem-solving, integrating business challenges, service architecture, and the technological landscape into your solutions.Lead the full software development lifecycle (SDLC), from requirements gathering and design through coding, testing, deployment, and monitoring. You will own your code, ensuring it remains robust and optimized for enhancements when opportunities arise.Design for performance, scalability, and resilience, ensuring your code operates flawlessly in a demanding environment where downtime, latency, and data loss are unacceptable.Collaborate within small, autonomous teams with rapid release cycles, leveraging agile methodologies to maintain high velocity while preserving necessary processes.Engage in continuous learning and knowledge sharing within the team, as our growth is contingent on the company’s collective evolution and constructive feedback. What We Expect from YouA solid understanding of common communication protocols, with comfort in using HTTP, WebSockets, and AMQP, alongside the ability to discern appropriate application contexts.Experience with at least one widely-used web framework, regardless of programming language. Our technology-agnostic platform allows engineers to choose the most suitable language for specific tasks, balancing cutting-edge solutions with proven technologies.A strong grasp of RDBMS concepts, including indexing, transactions, isolation levels, and locking mechanisms, with the skills necessary to design high-performance databases.

Join our talented team at devexperts as a Backend Engineer, where you'll play a pivotal role in developing cutting-edge software solutions. Your expertise in backend technologies will help us enhance our products and provide exceptional service to our clients.

Join the Global Bank tribe at SumUp, where we are developing the essential infrastructure and core services that empower our merchants with digital bank accounts. Our vision is to be the foremost banking partner for small merchants worldwide, delivering a seamless, straightforward, and affordable banking experience tailored to their unique needs.As a member of the Global Bank tribe, you will play a pivotal role in building SumUp's digital banking ecosystem. Collaborate within a diverse, autonomous, and cross-functional team that brings product ideas from concept to reality. Embrace the opportunity to work with talented colleagues from 32 different nationalities spread across cities like Cologne, Berlin, São Paulo, Sofia, London, and Vilnius, all driven by a shared commitment to ownership, purpose, and supporting small businesses in thriving.As a Senior Backend Engineer, you will take charge of enhancing and maintaining a high-throughput banking ecosystem for our merchants within the Global Bank Tribe. Your contributions will be instrumental in architecting and evolving our global banking platform, ensuring high availability, scalability, and observability across various regions. If you're eager to gain hands-on experience in building products for business accounts, card payments, and transfers across Europe and Latin America for SumUp's Global Bank, we invite you to embark on this exciting journey with us!

Join Our Mission to Empower Wealth BuildingAt trading212, we are revolutionizing the trading and investing landscape by crafting innovative products that resonate with our users.We champion a culture of excellence and agility, driving our success in a rapidly evolving market.Currently, we proudly serve over 4.5 million clients, managing more than €30 billion in assets—a true testament to the trust we have established in just a few years.Your RoleDesign and implement solutions with a comprehensive understanding of business challenges, our service architecture, and the relevant technologies and infrastructure.Be involved in every phase of the software development lifecycle (SDLC)—from gathering requirements and designing implementation to coding, testing, deploying, and monitoring. You will take full ownership of your code and ensure its continuous improvement.Develop robust solutions focused on performance, scalability, and resilience—your code will operate in a high-stakes environment where downtime, latency, and data loss are unacceptable.Collaborate within small, autonomous teams that operate on short release cycles. We value agile methodologies and a balanced approach to processes that avoid chaos without compromising speed.Engage in knowledge sharing and continuous learning with colleagues. As our company evolves, so must we, and constructive feedback is one of our strongest tools for growth. QualificationsProven experience in developing services within a microservice architecture, having contributed to a highly scalable and performant system comprising over 200 microservices.Strong understanding of common communication protocols. You should be adept at utilizing HTTP/WebSockets and AMQP, with the ability to choose the appropriate protocol based on the context.Familiarity with at least one widely-used web framework, regardless of programming language. Our language-agnostic system empowers engineers to select the most suitable language for specific tasks. We strive for a harmonious balance between cutting-edge technologies and proven solutions.A comprehensive understanding of system performance, scalability, and security best practices.

Join the Global Bank tribe where we are revolutionizing the banking infrastructure for merchants. Our mission is to empower small merchants worldwide with a digital business account that simplifies their banking needs, making us the go-to banking partner for them.As a Senior Backend Engineer, you will play a pivotal role in transitioning from fragmented regional systems to a unified global infrastructure, enabling millions of merchants to access seamless banking services tailored to their needs.Your expertise will be crucial in designing and developing a fully distributed, event-driven system that is resilient and compliant across multiple regions.In this role, you will primarily work with Kotlin while having the opportunity to engage with Elixir and Golang. We embrace Extreme Programming methodologies, focusing on small iterations, daily deliveries, and prioritizing technical design quality and deep problem-solving.Our technology stack includes Kotlin, Golang, Elixir, Java, AWS, Kafka, PostgreSQL, and Kubernetes, leveraged by observability tools such as Prometheus, Grafana, and Honeycomb. Additionally, we utilize AI-assisted development tools including Cursor and GitHub Copilot.

Role overview Brandwatch is looking for a Staff Software Engineer focused on Developer Experience (DevX). This position centers on strengthening the tools and workflows that help our engineering teams build and ship reliable products. The work directly supports a smoother, more effective developer environment across the company. Location This is a remote role based in Hungary or in Sofia, Bulgaria.

ABOUT TIDEAt Tide, we empower small and medium-sized enterprises (SMEs) to optimize their operations, saving both time and money. We provide not only business accounts and banking services but also a comprehensive suite of user-friendly administrative solutions ranging from invoicing to accounting.Tide is revolutionizing the small business banking sector with over 1.8 million members worldwide, including regions such as the UK, India, Germany, and France.By leveraging cutting-edge technology, we design all solutions with SMEs in mind. With rapid onboarding processes, minimal fees, and innovative features, we thrive on making data-driven decisions to fulfill our mission: to enable SMEs to focus on what they love.Tide Facts:Available for SMEs in the UK, India, Germany, and FranceOver 1.8 million members: 800,000 in the UK and 1,000,000 in India, with rapid growthSecured over $300 million in fundingMore than 2,500 diverse employees globallyHeadquartered in Central London, with a technology and member support center in Sofia, Bulgaria, and additional offices in Serbia, Romania, Lithuania, Hyderabad, Gurugram, New Delhi, Berlin, Paris, and Luxembourg.ABOUT THE TEAM:Our engineering team, comprising 40+ dedicated professionals, is focused on designing, developing, and managing a rich product catalog across various business domains (e.g., Payment Services, Business Services). With an extensive roadmap ahead, we constantly face exciting challenges. We trust our engineers to make impactful technical decisions that influence multiple teams and shape the future of Tide's Global One Platform. This is a unique chance to significantly contribute by taking ownership of engineering practices within a rapidly growing company!Our engineers work in small, autonomous teams dedicated to specific domains, overseeing the entire lifecycle of various microservices within Tide’s service catalog. They self-organize, collaborate to tackle technical challenges, and establish their own guidelines within the different Communities of Practice, regardless of their current position in our Growth Framework.ABOUT THE ROLE:Engage with our event-driven microservice architecture, which currently includes over 200 services managed by 40+ teams. You will be responsible for defining and maintaining the services your team owns (you design, build, run, and scale them globally).

Join Our Innovative Team as a Senior Backend Software Engineer! The Mobile Fulfilment Systems team at Ocado Group is pioneering state-of-the-art automation solutions for in-store and warehouse online order fulfilment. We harness the power of distributed backend systems, user-friendly mobile applications, and advanced autonomous robots to facilitate rapid, scalable, and cost-efficient order collection. As a key member of our Mobile Fulfilment Systems team, particularly within the In-Store Fulfilment (ISF) division, you'll be involved in designing and developing distributed cloud-based systems, PWA mobile applications, and web technologies aimed at automating the fulfilment of online customer orders at scale. What is In-Store Fulfilment? ISF is a comprehensive cloud-based solution that empowers stores to efficiently fulfil customer orders, enhancing the shopping experience while minimizing operational costs. We are currently operational in over 1,000 stores across 11 countries and 4 continents, handling more than 300,000 customer orders weekly. In Your Role as a Senior Software Engineer, You Will: Design, develop, and maintain large-scale, high-availability distributed systems. Lead technical initiatives from conception through to implementation, fully owning the planning, coordination, design, and execution processes. Ensure solutions consistently meet quality standards by adhering to best practices in testing, code quality, monitoring, and alerting. Contribute to the long-term architectural and product vision. Utilize AI tools, such as Claude Code, Gemini, and GitHub Copilot, to enhance our development processes. Engage in all phases of the software development lifecycle within an agile team framework. Continuously seek to enhance our processes, workflows, and tools. Collaborate closely with business and product partners to translate system requirements into engineering solutions. Participate in our on-call rotation to support production services. Mentor and train both new and existing team members in their professional development.

Our mission is to empower individuals to create wealth.At Trading 212, we are transforming the landscape of trading and investing by developing outstanding products that our users adore.Our dynamic team is composed of highly motivated individuals who pursue excellence and cherish autonomy.With over 4.5 million clients and more than €30 billion in assets under management, our growth and trust in the market speak volumes about our success.We are in search of passionate and experienced Principal Software Engineers to drive innovation and scalability in our systems.

Role Overview Cision is looking for a Lead DevOps Engineer (Observability & Developer Experience) to guide two critical areas within our engineering organization. This remote position is open to candidates based in Hungary or Sofia, Bulgaria. This role focuses on supporting our observability platform and developer tools. The Lead DevOps Engineer will set technical direction for monitoring, logging, CI/CD, and automation, while remaining hands-on with engineering work. Collaboration with cross-functional teams is central, as is a commitment to continuous improvement and innovation across our systems. What You Will Do Lead and mentor a team of DevOps/SRE engineers working on observability (monitoring, logging, alerting) and developer experience (CI/CD pipelines, internal tools). Define the vision and roadmap for observability and developer productivity, aligning with business and engineering needs. Design, implement, and manage monitoring and logging infrastructure to provide clear visibility into system health and performance. Develop and maintain CI/CD pipelines and automation frameworks to support secure, rapid deployments and improve developer workflows. Work closely with engineering and product teams to deliver cross-functional initiatives that build reliability and efficiency into our services. Establish and share best practices for infrastructure management, incident response, and post-mortem analysis. Help define and implement AI tooling and standards, making scalable and secure AI solutions available to developers throughout the company. About Cision Cision supports individuals who want to make a real impact. We value every voice and welcome new ideas, believing that diverse perspectives drive our collective success. Our global team encourages curiosity, collaboration, and innovation, offering the chance to contribute meaningfully to the brands we serve. We aim to redefine communication and foster strong relationships. Whether solving complex problems or building new solutions, employee growth is a shared achievement. Join us as we shape the conversations of tomorrow.

At Cision, we are dedicated to empowering individuals to create meaningful impacts. Your voice matters here, your ideas are valued, and your unique perspective contributes to our collective success. As a member of our global team, you will flourish in a culture that promotes curiosity, collaboration, and innovation, all while making significant contributions to the brands we support. Join us in redefining communication and forging authentic connections that resonate. Whether you are tackling complex challenges or spearheading innovative initiatives, your growth is our achievement, and together, we’ll shape the conversations of the future. Empower your impact at Cision. Be seen, be understood, be you.

At SumUp, we celebrate the everyday heroes who possess the courage to pursue their passions and the determination to turn their dreams into reality. Our mission revolves around empowering small business owners with innovative, user-friendly financial solutions that simplify the management of their enterprises. With a founder's mentality and a 'team-first' attitude, our diverse teams across Europe, South America, and the United States collaborate to ensure that these entrepreneurs can thrive in their endeavors. The Global Bank team at SumUp is responsible for developing the foundational infrastructure and services that provide merchants with digital bank accounts, enabling them to manage their finances efficiently and reliably. Within this team, the Balance Management Squad is pivotal. We are currently nearing a significant milestone: the consolidation and modernization of our balance management system in Europe. Our next ambitious project is to establish a global transaction history service—a unified platform that offers merchants consistent and transparent insights into their financial activities across all regions. As a Backend Engineer, you will play a crucial role in modernizing existing systems while balancing innovation and stability. You will collaborate with teams across various regions to build reliable services that can navigate diverse markets with unique regulatory requirements. If you are passionate about solving complex problems in high-load systems, have a curiosity for banking, and are eager to join a team that embraces challenges, we would love to connect with you.