
Sumup · Sofia
SumUp gives small businesses the tools they need to get paid, manage their money, and grow - today, over 4 million merchants across 37 markets worldwide rely on...
SumUp gives small businesses the tools they need to get paid, manage their money, and grow - today, over 4 million merchants
across 37 markets worldwide rely on SumUp to do exactly that.
The Bank Web squad sits within SumUp's Bank domain and owns the web experience across our banking surfaces - from the business
account dashboard that merchants use daily, to the back-office tooling that powers the support teams behind them. The team has a
clear mission: make Bank Web a genuinely first-class platform, on par with our mobile applications in quality, reliability, and
performance.
Joining now means being part of a team that’s at a key growth point - modernization work, growing scope across markets, and making
architectural decisions that will shape how millions of merchants experience SumUp's banking products.
👉 Take a look at our Sofia office
What you'll do
observability, and production maintenance
that power our banking platform
reduce technical debt and accelerate future delivery
domain
You'll be great for this role if…
isolated UI components
just consuming them; backend experience in Node, Kotlin, Java, or Golang is valued
connect to backend services
and reliability
also includes Node.js, Kotlin, Java, Go, Angular, AWS and Kafka. Prior experience with all of these is not required, but
familiarity with most of them is a plus
find the right solution
workflows is a plus
Why you should join SumUp
our modern Sofia office. This involves an office-first setup
environment where everyone's perspectives are respected and embraced
advance your career through further education
special leave options
About SumUp
Be empowered to do more that matters.
At SumUp, we're on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them
to thrive. Today, over 4 million businesses in 37 markets rely on SumUp as their financial partner to manage payments, finance and
customer relationships.
Our commitment to small businesses is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities, united by
global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping
our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for
personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone
belongs and feels supported, no matter how they identify.
SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't
make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality,
sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by
company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form
is strictly prohibited. Discover more about our culture and opportunities on our careers website, and follow our journey on
LinkedIn, Instagram, and TikTok.
Job Application Tip
We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is
only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.
Job Application Tip
We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is
only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.
Company Mission Payhawk is a leading global spend management solution for scaling businesses. Headquartered in London and combining company cards, reimbursable expenses and accounts payable into a single product; its future-facing technology enables finance teams to control and automate company spending at scale. The Payhawk customer base includes fast-growing and mature multinational companies in 32 countries including LuxAir and Wagestream. With offices in New York, London, Berlin, Munich , Barcelona, Paris, Amsterdam, Vilnius and Sofia; Payhawk is backed by renowned investors such as Lightspeed Venture Partners, Greenoaks, QED Investors, Bek Ventures and Eleven Ventures. Our values include supporting flat hierarchies, taking ownership and responsibility, seeking and providing feedback, managing constructive critique, and speaking our minds. We understand that the best ideas don’t all come from the same place, so we encourage diversity and inclusion in all areas of our work. The future of fintech is about more than money, and we believe in work-life balance, continual learning, and empowered teams. We’re also on a journey to measure and improve our environmental and social impact. From virtual cards to digital subscriptions, our software and automation help take paper out of the equation for our customers, too. We’re changing the world of payments, and we’re looking for an exceptional team to help us. About the Role Automation, Integrations, Agents, Platform, Retrieval & AI UX As part of our Efficiency team, you will upskill and uplift every role with AI‑powered tools - automating workflows and building secure, reliable assistants, agents, and role “digital twins.” Just like broader Payhawk we obsess over customer success, our customers are every Hawk and every Payhawk customer, and we measure impact by adoption, task success, and time saved. We design human‑centered AI and manage risk responsibly. You’re a product‑minded software engineer who designs and ships end‑to‑end AI solutions: chat UIs, APIs, orchestration, data pipelines, retrieval, evals, and guardrails. You love jumping between frontend, backend, prompts, schemas, observability, and Kubernetes to deliver measurable time savings for Hawks. Rigorous studies show AI assistance can raise knowledge‑worker productivity, especially for less‑experienced workers - so we measure against hours saved and task success from day one. HOW WE WORK * We behave like a Platform + Enabling capability that accelerates stream‑aligned teams. * We measure delivery with DORA’s Four Keys and product value with adoption & time saved. See why: DORA 2024 report. * We build tools‑using agents via MCP and rely on RAG / Hybrid RAG for grounded answers. RESPONSIBILITIES * Build UI + backend for chat/agent experiences; own discovery → shipping → monitoring. * Orchestrate tool‑using agents via MCP; design safe tool APIs and connectors. * Implement and iterate RAG / Hybrid RAG (dense + BM25) with quality evals (faithfulness, groundedness, latency); manage prompt & retrieval versioning. * Data work: build ingestion/ETL, chunking/metadata, access‑aware retrieval; ensure lineage and governance. * Reliability: tracing, cost & latency SLOs, autoscaling; CI/CD with quality gates (offline/online LLM evals). * UX & prompts: craft conversational flows using People + AI Guidebook patterns; instrument analytics and A/Bs for task success and satisfaction. * Security & risk: apply applicable security standards such as (but not limited to) NIST AI RMF guardrails; work with Security/Legal on data handling and auditability. REQUIREMENTS * 4+ years experience; expert in Node.js/TypeScript/React/PostgreSQL; CI/CD & cloud (GCP/K8s). * Shipped LLM apps (agents, function/tool use, retrieval); strong API design & data modeling. * Comfortable with Python for data/ETL; vector stores; analytics instrumentation. * Bachelor's degree in Computer Science (or related field). * Experience with agile processes, continuous delivery, and continuous integration. * Ability to multitask, organize, and prioritize work. * Exceptional integrity and work ethic. NICE TO HAVE * Frontend experience, Kafka, experimentation platforms, prior experience with MCP servers/clients. Company Benefits * Competitive compensation package based on experience. * 30 days holiday paid leave. * One week exchange policy to another Payhawk office (London, Berlin, Barcelona, Paris, Amsterdam and Vilnius). * Flexible working hours and opportunity to work from home. * Regular team-wide events. * Additional medical care. * MultiSport card fully funded by us. * Company office massages. * Personal assistant service. * Opportunity to use the Payhawk product (that is, essentially, built by you).
Company Mission Payhawk is a leading global spend management solution for scaling businesses. Headquartered in London and combining company cards, reimbursable expenses and accounts payable into a single product; its future-facing technology enables finance teams to control and automate company spending at scale. The Payhawk customer base includes fast-growing and mature multinational companies in 32 countries including LuxAir and Wagestream. With offices in New York, London, Berlin, Munich , Barcelona, Paris, Amsterdam, Vilnius and Sofia; Payhawk is backed by renowned investors such as Lightspeed Venture Partners, Greenoaks, QED Investors, Bek Ventures and Eleven Ventures. Our values include supporting flat hierarchies, taking ownership and responsibility, seeking and providing feedback, managing constructive critique, and speaking our minds. We understand that the best ideas don’t all come from the same place, so we encourage diversity and inclusion in all areas of our work. The future of fintech is about more than money, and we believe in work-life balance, continual learning, and empowered teams. We’re also on a journey to measure and improve our environmental and social impact. From virtual cards to digital subscriptions, our software and automation help take paper out of the equation for our customers, too. We’re changing the world of payments, and we’re looking for an exceptional team to help us. About the Role To achieve our visionary goals, we are scaling up our robust engineering team and looking for a Full Stack Software Engineer to meet the compelling challenges we face. Our product consists of many services that are not limited to a single technology so it’s important that you are technology agnostic and eager to learn new stuff. You’ll be responsible for delivering entire, highly complex features to production. As part of a team of talented and highly experienced individuals, you’ll have the opportunity to shape everything. Our goal is to produce the best solution for our customers. Being part of the Payhawk team means that you’ll be developing a world-class product in the fast-growing fintech industry. We deliver an exceptional solution, and to continue doing so, we seek out the top 1% engineering talent. Responsibilities * Contribute to the implementation of new features and resolution of bugs in the domain area, ensuring high-quality, maintainable code that aligns with team standards. * Participate in the complete product development lifecycle, including planning, implementation, code reviews, testing, deployments, and post-release support. * Write modular, clean, and testable code that avoids language or structure-related mistakes. Apply appropriate testing strategies (unit, integration, e2e tests) to ensure strong coverage and reliability. * Take ownership of well-defined tasks, work autonomously, and proactively seek input when facing uncertainty, ensuring clarity on scope and edge cases before starting. * Collaborate effectively with product managers, designers, and engineers to understand problems, evaluate trade-offs, and deliver solutions that support business goals. * Review pull requests constructively, communicate clearly about your work, and proactively share updates, blockers, or risks. * Develop a strong understanding of the domain and broader system context to contribute to accurate estimations and high-quality delivery. Requirements * Advanced programming experience and superior knowledge of programming languages and technologies: Node.js, TypeScript, PostgreSQL, Kubernetes, Docker, Google Cloud, React, React Native, Apache Kafka. * Bachelor's degree in Computer Science (or related field). * 3+ years of relevant work experience. * Experience with agile processes, continuous delivery, and continuous integration. * Ability to multitask, organize, and prioritize work. * Exceptional integrity and work ethic. * Nice to have: Experience working with LLMs, AI-driven architectures, and autonomous agents, including vector databases, embedding models, and MLOps practices. Company Benefits * Competitive compensation package based on experience * 30 days holiday paid leave * One week exchange policy to another Payhawk office (London, Berlin, Barcelona, Paris, Amsterdam and Vilnius) * Flexible working hours and opportunity to work from home * Regular team-wide events * Additional medical care * MultiSport card fully funded by us * Company office massages * Personal assistant service * Opportunity to use the Payhawk product (that is, essentially, built by you)
Company Mission Payhawk is a leading global spend management solution for scaling businesses. Headquartered in London and combining company cards, reimbursable expenses and accounts payable into a single product; its future-facing technology enables finance teams to control and automate company spending at scale. The Payhawk customer base includes fast-growing and mature multinational companies in 32 countries including LuxAir and Wagestream. With offices in New York, London, Berlin, Munich , Barcelona, Paris, Amsterdam, Vilnius and Sofia; Payhawk is backed by renowned investors such as Lightspeed Venture Partners, Greenoaks, QED Investors, Bek Ventures and Eleven Ventures. Our values include supporting flat hierarchies, taking ownership and responsibility, seeking and providing feedback, managing constructive critique, and speaking our minds. We understand that the best ideas don’t all come from the same place, so we encourage diversity and inclusion in all areas of our work. The future of fintech is about more than money, and we believe in work-life balance, continual learning, and empowered teams. We’re also on a journey to measure and improve our environmental and social impact. From virtual cards to digital subscriptions, our software and automation help take paper out of the equation for our customers, too. We’re changing the world of payments, and we’re looking for an exceptional team to help us. About the Role To achieve our visionary goals, we are scaling up our robust engineering team and looking for a Full Stack Software Engineer to meet the compelling challenges we face. Our product consists of many services that are not limited to a single technology so it’s important that you are technology agnostic and eager to learn new stuff. You’ll be responsible for delivering entire, highly complex features to production. As part of a team of talented and highly experienced individuals, you’ll have the opportunity to shape everything. Our goal is to produce the best solution for our customers. Being part of the Payhawk team means that you’ll be developing a world-class product in the fast-growing fintech industry. We deliver an exceptional solution, and to continue doing so, we seek out the top 1% engineering talent. Responsibilities * Lead the build of new product features and maintain existing ones by driving impactful engineering initiatives and owning end-to-end delivery. * Participate in the full software development lifecycle, including frontend, backend, testing, deployment, and LLM-based functionalities where applicable, while contributing to the architecture and proposing scalable, sustainable solutions. * Collaborate with product managers and designers to capture requirements and gain a strong business perspective on the features being implemented. * Break down complex, ambiguous problems into well-scoped and clearly defined tasks, ensuring alignment with product and technical goals. * Write scalable, high-performance, and maintainable code, ensuring testability, coverage, continuous integration, and backward compatibility. * Own feature delivery from discovery through deployment and monitoring, proactively addressing blockers and risks with minimal supervision. * Mentor and support other engineers through knowledge sharing, constructive feedback, and code reviews. * Collaborate across teams to remove dependencies, foster alignment, and ensure the team’s work fits into the broader technical direction. Requirements * Advanced programming experience and superior knowledge of programming languages and technologies: Node.js, TypeScript, PostgreSQL, Kubernetes, Docker, Google Cloud, React, React Native, Apache Kafka. * Bachelor's degree in Computer Science (or related field). * 6+ years of relevant work experience. * Experience with agile processes, continuous delivery, and continuous integration. * Ability to multitask, organize, and prioritize work. * Exceptional integrity and work ethic. * Nice to have: Experience working with LLMs, AI-driven architectures, and autonomous agents, including vector databases, embedding models, and MLOps practices. Company Benefits * Competitive compensation package based on experience * 30 days holiday paid leave * One week exchange policy to another Payhawk office (London, Berlin, Barcelona, Paris, Amsterdam and Vilnius) * Flexible working hours and opportunity to work from home * Regular team-wide events * Additional medical care * MultiSport card fully funded by us * Company office massages * Personal assistant service * Opportunity to use the Payhawk product (that is, essentially, built by you)