Senior AI Backend Engineer
SumUp is seeking a Senior Backend Engineer to help build SumUp Edge, an AI-powered co-pilot that turns raw merchant data into proactive, real-time business insights. In this role you will architect the systems connecting the data platform, LLM orchestration layer and merchant-facing APIs, laying the foundations of the company's next generation of AI products. You will collaborate closely with machine learning engineers, data scientists and product managers, working from the Berlin office in an office-first setup.
Responsibilities
- ▹Architect, design, develop and deploy AI solutions and systems in production, ensuring reliability, high performance and scalability
- ▹Design and build the orchestrator service coordinating AI components, data flows and external services to deliver real-time insights
- ▹Develop and maintain scalable ETL pipelines or MCPs processing heterogeneous data (text, images, audio) into the AI system
- ▹Build and optimise the LLM Gateway infrastructure, including authentication, rate limiting, load balancing and vector database management for the RAG system
- ▹Create robust, high-performance APIs handling multimodal data structures and high-volume requests with low latency
- ▹Implement observability tooling (telemetry, logging, tracing) to support auditing and continuous improvement of AI interactions
- ▹Mentor backend engineers and contribute to engineering standards, code reviews and a culture of technical excellence
- ▹Collaborate with data scientists, product managers and business stakeholders to deliver state-of-the-art AI solutions
Requirements
- ▹Bachelor's or master's degree in Computer Science, Engineering or a related field
- ▹6+ years of experience developing software products (ML or AI related is a plus)
- ▹Advanced proficiency in Python, with hands-on experience building and scaling production backend systems using Kubernetes, Docker, Airflow and Spark
- ▹Strong knowledge of cloud infrastructure (AWS, S3) and CI/CD practices
- ▹Experience designing APIs and working with distributed data systems and message brokers such as Kafka or RabbitMQ
- ▹Familiarity with LLMs, GenAI tooling and machine learning concepts
- ▹Experience with status monitoring using cloud-native or 3rd party tools (e.g. Prometheus, CloudWatch) and LLM traceability
- ▹Excellent communication and collaboration skills for cross-functional teams
- ▹Ability to adapt to a fast-paced environment and quickly learn new technologies
Soft skills
What we offer
- ▹Virtual Stock Option programme (stake in SumUp's future success)
- ▹Annual L&D budget of €2000 for individual development, conferences and further education
- ▹Corporate pension scheme matching up to 20% of contributions
- ▹28 days of paid leave plus public holidays and special leave days
- ▹Urban Sports Club subsidy, Kita placement assistance and subsidised office lunches
- ▹1-month sabbatical after 3 years of service (Break4me)
- ▹Referral bonus
About the company
SumUp is on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them to thrive. Over 4 million businesses in 37 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships. Its diverse team of over 3,000 SumUppers from over 90 nationalities is united by global collaboration and an innovative mindset. SumUp is proud to be an Equal Employment Opportunity employer.