Senior Software Engineer – API Development (Python)

About Buynomics: 

“What will customers buy?” This is the critical question underlying all commercial decisions for companies. At Buynomics, we have pioneered Virtual Customer technology to answer this question 100x faster and more precisely than traditional solutions. By replacing gut feeling and spreadsheets, we enable companies to make data-driven, transparent, and customer-centric decisions.

Our platform serves as the operating system for commercial decisions, providing businesses with a unified source of truth to address market-facing questions like pricing, product offerings, and promotions. Leveraging large-scale simulation technologies, we digitize customer behavior to predict purchase patterns in any environment. Our clients use Buynomics to optimize decisions on pricing, portfolio structure, promotions, trade terms, and beyond.

We are looking for a talented Senior Software Engineer – API Development (Python) to join our growing Machine Learning team. In this role, you will play a key part in designing and building high-performance, secure, and scalable APIs that power our platform and services. This is an exciting opportunity to work on backend systems that support real-time and batch processing, contribute to architectural decisions, and collaborate with cross-functional teams in a modern, fast-paced tech environment. Your work will directly impact the reliability and scalability of our infrastructure as we continue to grow.

What you'll do: 

• Design, build, and maintain robust, scalable, and secure RESTful APIs using Python (FastAPI, Flask, or Django).
• Develop and manage asynchronous task workflows using Celery, Dramatiq, or equivalent libraries.
• Implement message brokers and queues (e.g., RabbitMQ, Redis, Kafka) for background job processing.
• Collaborate with DevOps to design and maintain scalable deployment architectures, including load balancing and service orchestration (e.g., Kubernetes, Docker) – both for batch and real time processing.
• Monitor, debug, and optimize API performance and task processing pipelines.
• Write clean, maintainable, and well-documented code with a focus on testability and automation.
• Participate in code reviews, technical planning sessions, and architectural discussions.

What you'll need:

• 5+ years of experience in Python backend development.
• Proficiency in building and consuming RESTful APIs.
• Strong knowledge of asynchronous programming and background task management.
• Hands-on experience with task queues and brokers (e.g., Celery + Redis/RabbitMQ, or equivalent).
• Experience with load balancing strategies in distributed systems.
• Familiarity with containerization (Docker) and orchestration tools (Kubernetes is a plus).
• Experience with version control systems like Git.

Preferred Qualifications:

• Experience working in a machine learning context, ideally with real time predictions as a service
• Experience with API documentation tools (Swagger/OpenAPI).
• Knowledge of FastAPI.
• Familiarity with monitoring tools such as Prometheus, Grafana, or ELK Stack.
• Exposure to CI/CD pipelines and cloud platforms (AWS, GCP, or Azure).
• Experience working with relational (PostgreSQL, MySQL) and NoSQL (MongoDB, Redis) databases. Ability to design schemas and optimize queries.

What we offer:

• Dynamic Environment: Join a truly international and diverse team where your ideas matter.
• Flexible Work Model: Enjoy a hybrid setup with an office in Cologne.
• Professional Growth: Take advantage of our employee development and education budget to enhance your skills.
• Local Language Classes: Participate in language lessons to support your integration and personal development.
• Health and Fitness Benefits: Access comprehensive health and fitness perks to keep you at your best.

 

To ensure a smooth and efficient process and that no applications are overlooked, please apply directly to the role. While we'd love to respond to everyone who reaches out, applying ensures that your application is properly tracked and considered.

Buynomics is proud to be an equal opportunity employer. This means that we don’t discriminate based on race or ethnic origin, color, the language(s) you speak, where you (or your parents) are from, or whether or not you consider yourself to have a disability. Neither will your age, gender, gender identity, sexual orientation, religion, beliefs, or political opinions play a part in your application with us. We’re a diverse team in so many ways, and we love it that way.