Mid-level Java Engineer (AI Agents, MCP)

Contract: B2B, Full-time or Part-Time (from 15-20 hours/week)

Location: 100% Fully Remote

Start Date: Immediate

Polish language required

🚀 The Opportunity

We are seeking a highly skilled Mid-Level Java Engineer for a critical B2B contract.

You will be a key developer building a new MCP (Model Context Protocol) Server for a leading global insurance company. This is a cutting-edge role. Instead of a traditional backend, you will be building the server-side implementation of the Model Context Protocol, a new open standard for AI. Your work will create the secure, standardized "tools" and "resources" that enable the company's proprietary AI agents to interact safely and effectively with live enterprise systems, databases, and APIs. If you are passionate about building the real-world plumbing that connects next-generation AI to enterprise data, this is the role for you.

💻 What You'll Be Doing

• Design & Build: Architect and develop a high-availability, scalable MCP Server using Java 17+ and Spring Boot.
• Implement the MCP Standard: Utilize the Spring AI MCP integration (or the core Java SDK) to expose internal data sources (databases, filesystems) and business logic (APIs) as "tools" and "resources" for the AI agent.
• Develop Data Contracts: Define and implement the JSON-RPC 2.0 and Server-Sent Events (SSE)-based transport layer for the protocol (Spring WebFlux or WebMVC)
• API & Data Integration: Create robust connectors (e.g., REST, gRPC, Kafka consumers) to wrap existing internal insurance systems, making them securely accessible to the MCP server.
• Collaborate: Work directly with the client's AI and data science teams to define the capabilities, schemas, and API contracts the AI agent needs to perform its tasks.
• Ensure Quality: Write clean, testable, and efficient code, ensuring the platform meets the high-security and reliability standards of the financial services industry.

🔧 What We're Looking For

• Core Java & Spring: 3-5+ years of professional experience in Java development, with a strong command of Java 11/17+ and deep expertise in the Spring Framework (especially Spring Boot).
• Reactive Programming: Experience with or strong understanding of reactive principles and frameworks (e.g. Spring WebFlux)
• API & Microservice Expert: Proven experience in designing, building, and securing scalable RESTful APIs and microservices.
• Data Integration: Strong proficiency with SQL (e.g., PostgreSQL) or NoSQL databases and experience with message brokers (e.g., Kafka, RabbitMQ).
• Autonomy: Excellent communication skills and the discipline to work effectively in a remote, part-time, and independent B2B contract setting.

⭐ Nice to Haves

• Direct experience with the Model Context Protocol (MCP) itself.
• Experience with Spring AI, LangChain, or other AI orchestration frameworks.
• Familiarity with the Azure cloud platform and containerization (Docker, Kubernetes).
• Prior experience in the insurance or financial services industry.

If you are a Java Engineer ready to build the critical infrastructure for a cutting-edge AI agent, please apply now. We are reviewing applications on a rolling basis.