Senior Java Engineer - AI Platform (m/f/d)

We are looking for a Senior Backend Engineer to join our AI speedboat team at Sport Alliance. You’ll be the technical backbone of our AI platform, designing and building Java services for multi-agent conversational AI, predictive analytics, and member engagement. This hands-on role lets you own the architecture and implementation of production AI systems in a small, fast-moving team.

Salary range: 22,000 - 26,000 PLN net + VAT B2B Your position in our team

• Lead the design and development of core Java services powering our multi-agent AI platform.
• Architect integrations with Magicline ERP for memberships, bookings, and payments.
• Build LLM orchestration infrastructure, managing prompts, model routing, and fallback strategies.
• Implement authentication, authorization, and multi-tenancy for enterprise clients.
• Develop data pipelines and feature stores to feed predictive ML models.
• Create robust APIs, monitoring, and automated testing for AI systems.
• Contribute to key technical decisions around model selection, deployment, and scaling.

Your profile

• 5+ years in backend (Java) or full-stack engineering.

• Strong system design: microservices vs monoliths, synchronous vs asynchronous patterns.

• Hands-on with Java frameworks (Spring Boot), API design, and database modeling.

• Familiarity with AI/ML infrastructure or building integrations with ML models.

• Experienced in multi-tenant SaaS, CI/CD, monitoring, and production operations.

• Collaborative mindset: code reviews, mentoring, and technical discussions.

• Fluent English (C1); German is a plus.

• Nice to have:

• Full-stack: React + TypeScript

• Experience with prompt engineering, agent frameworks, or LLM-powered apps

• Background in B2B SaaS, ERP, CRM, or complex operational platforms

• Event-driven architectures, Kafka, RabbitMQ

• GDPR & EU AI Act knowledge

• Experience in fitness, health, or membership-based businesses

Your benefits with us

• Benefits package – private medical care and a sports card to support your health and well-being
• Flexible working hours – manage your schedule and enjoy a real work-life balance
• Flexible work model – work fully remotely or combine it with on-site collaboration at our modern office in Warsaw
• Flexible employment options – choose the type of contract that best suits your needs
• Access to Udemy Business – grow your skills with thousands of high-quality online courses
• Unique experience in the Fitness and SaaS industry – join a market-leading company in a dynamic, fast-growing field
• International team – collaborate with talented colleagues from around the world in a diverse and inclusive environment
• Unforgettable company events – take part in engaging team-building activities and memorable celebrations
• No dress code – express your personal style and feel comfortable at work