Senior Software Developer (AI+Java Experience)

Berlin, Berlin, Germany

Overview

We’re forming a new squad at Lightspeed focused on building AI-powered tools and capabilities . This includes working with LLMs, agent frameworks , and other emerging AI technologies to build internal tools, extend our product suite with new AI features, and help other teams across the company adopt AI effectively.

You’ll be part of a highly collaborative and innovative team of developers, product managers, and designers. Your role will involve backend engineering—especially in our Spring Boot Java ecosystem—while also exploring and applying modern AI techniques to solve real problems. This is a hands-on engineering role and we are specifically looking for a versatile Java developer with a passion for Artificial Intelligence.

What you’ll be responsible for

• Building and maintaining backend services and APIs in a Spring Boot Java environment
• Designing and implementing AI-powered tools and product features
• Collaborating with other teams to help them integrate LLMs and AI patterns
• Exploring and applying LLM capabilities such as summarization, classification, RAG, and prompt pipelines
• Writing clean, maintainable, and well-tested backend code
• Ensuring reliability, performance, and scalability of the systems you build
• Staying up to date with developments in the AI space and sharing insights with your team

Who you are

You’re excited about building practical, AI-enabled systems that make work easier and products better. You enjoy solving hard problems with clean code and clear thinking. You’re curious about AI and open to learning new patterns, frameworks, and tools.

You bring deep backend experience, work well in teams, and care about building things that are actually useful.

Requirements

• At least 5 years of experience in backend development
• Proven technical leadership
• Strong Java and Spring Boot experience in production environments
• Solid understanding of REST APIs, databases (SQL/NoSQL), and system architecture
• Familiarity with Docker, CI/CD pipelines, and Kubernetes
• Strong communication and collaboration skills
• Comfortable writing well-structured, maintainable code
• Professional experience building or integrating AI-powered systems in production, including work with LLM APIs (e.g. OpenAI, Claude), prompt engineering, or agent frameworks
• Experience building internal tools or customer-facing AI features

What will increase your chances

• Experience with one additional backend language (especially Python)
• Familiarity with observability tools and performance monitoring
• Understanding of security, access controls, and API standards
• Knowledge of vector search, semantic retrieval, or document indexing

What’s in it for you

• Lots of autonomy, flexible work culture
• Genuine career growth opportunities within a company that's continuously expanding
• Make a meaningful impact by helping teams and customers work more effectively with AI
• Be part of a team large enough for growth yet agile enough for real impact
• Work on high-traffic products with a global user base
• Opportunity to work alongside other highly skilled engineers, learn and expand your skill set, forge wonderful relationships and make your mark within the diverse and inclusive Lightspeed culture, a true Canadian tech success story

Lightspeed is building communities through commerce, and we need people from all backgrounds and lived experiences to do that.