Senior Backend Software Engineer

Your tasks We are looking for a Senior Backend Software Engineer to join our cross-functional product team. You will play a pivotal role in designing, developing, and scaling the backend systems that power our AI-driven negotiation platform. You'll work closely with product managers, frontend engineers, and data teams to build robust, secure, and highly available services. Key Responsibility: Architect, develop, and maintain scalable backend services using Python and FastAPI, following Hexagonal (Ports & Adapters) architecture principles.Design and build serverless applications using AWS Lambda, Step Functions, and API Gateway.Model and manage data using DynamoDB, ensuring performant and cost-effective access patterns.Implement secure authentication and authorization flows using Cognito.Build event-driven and asynchronous workflows using Step Functions and SES for transactional messaging.Integrate with IoT Core to support device connectivity and real-time data ingestion.Ensure code quality through code reviews, automated testing, and adherence to best practices.Collaborate with cross-functional teams to define and deliver complete, end-to-end solutions.Write comprehensive unit, integration, and end-to-end tests to ensure code quality and maintainability. Your profile 5+ years of professional experience building and maintaining backend systems in production.Expert-level proficiency in Python, with hands-on experience using FastAPI.Hands-on experience designing systems using Hexagonal architecture (or similar patterns like Clean Architecture or Ports & Adapters).Strong experience with AWS serverless services: Lambda, Step Functions, API Gateway.Hands-on experience with AWS SAM (Serverless Application Model) for building and deploying serverless applications.Solid experience with DynamoDB or other NoSQL data stores, including data modeling and access pattern design.Experience with AWS Cognito for authentication and authorization.Experience with SES or similar services for transactional email/messaging.Familiarity with IoT Core or event-driven/IoT architectures.Proficient with version control systems such as Git (GitLab, GitHub).Familiarity with Agile development methodologies, CI/CD pipelines, and automated testing.Strong technical spec writing skills, with the ability to translate requirements into clear, actionable documentation.Excellent communication skills, a collaborative mindset, and a strong sense of ownership. Bonus Qualifications Experience with Infrastructure as Code tools beyond SAM (e.g., Terraform, AWS CDK).Exposure to event-driven architectures and messaging systems (e.g., SQS, SNS, EventBridge).Experience with other cloud platforms (e.g., Azure, Google Cloud Platform) in addition to AWS.Experience using AI tools for development to boost productivityIntegrating AI/LLM capabilities into backend systems.Understanding of observability practices (logging, tracing, monitoring) in distributed/serverless systems.Experience with containerization (Docker) and orchestration.Interest or experience in game theory, negotiation systems, or applied AI/ML backends.Experience working in regulated or high-security environments (data privacy, compliance). Why us? At Beroe X nnamu GmbH, we prioritize a balanced work-life experience. Here’s what we offer you: 4-Day Work Week & up to 24 Days Paid Vacation – More time to rechargeMonthly Benefits Allowance – €40/month in vouchers for fitness and other perks with ProbonioCompetitive Compensation – Fair salary and comprehensive benefits. Flexible Work Arrangements – Work the way that suits you. Professional Development – Access to training and certifications. Team Events – Bi-annual company events and Quarterly team lunch get-togethers. Work Abroad Flexibility – Remote work from the EU or selected non-EU countries for up to 8 weeks a year with travel insurance coverage We operate on a hybrid model with offices in Berlin and Munich, offering a 32-hour, 4-day workweek. This means: In-Office Collaboration: Work from the office two days a weekManage Your Own Hours: Flexibility to work around your needs as long as team goals are met. Our Culture   We are committed to fostering a collaborative, innovative and inclusive work environment where everyone’s ideas matter. We know that diverse teams lead to better outcomes and welcome applicants from all backgrounds. About Us At Beroe x nnamu GmbH, we are committed to empowering procurement teams to make informed, strategic decisions that drive real impact. By integrating AI and game theory, our Software as a Service (SaaS) platform, nnamu.negotiations, delivers a groundbreaking approach to complex, yet autonomous negotiations.    nnamu.negotiations delivers additional total-value-of-ownership savings efficiently and effectively for buyers with no prior knowledge of game theory required. By combining our world class proprietary AI with an unmatched, unique database of over EUR 400bn actual game theory project data we help clients uncover incremental value in their negotiations, driving outcomes that were previously out of reach.   Beroe x nnamu GmbH is now a Beroe, Inc. group entity. Beroe is a global leader in procurement intelligence. Beroe has been on procurement’s leading edge since the company’s founding in 2006, bringing a world of insights forward. The unique combination of Beroe’s expertise, AI tools, and vast amounts of reliable data enable organizations to make smarter, faster, better procurement decisions. Not tomorrow, not today, but now. Selected by ProcureTech as one of the “most pioneering Analytics, Data and Intelligence solutions in 2024”, Beroe helps thousands of organizations sift through the data noise, mitigate risk, face fewer surprises, and ultimately gain a competitive edge.  With nnamu’s cutting-edge AI and Beroe’s trusted market intelligence, we are unlocking game-changing possibilities for procurement teams worldwide   The Challenge We are Solving   Despite the proven potential of game theory to enhance negotiation outcomes significantly – potentially unlocking an incremental USD 1 Trillion of value – its application in business negotiations remains rare, inconsistent, and hard to scale. This gap presents a vast opportunity but also a challenge that many companies have yet to overcome. Beroe x nnamu GmbH is pioneering the use of AI-powered game theory to make complex negotiation strategies accessible, scalable, and incredibly effective for organizations worldwide.