Senior Software Engineer - Java

At FlowX.AI we are building the engine for the next generation of cognitive enterprise systems - because we believe enterprise software is the software layer that our civilization relies on. Today, our AI platform is used in large banks and empowers both new and experienced users to leverage AI to build complex mission critical applications.

We believe amazing things are created by small teams of brilliant people. Our engineering team today is an all-star team - and we work to keep it that way. It’s quality over quantity.

We're building high-performance AI agents on a modern polyglot stack (Java 21 + Python 3.12), and we need a world-class engineer to own core pieces of the platform.

This is a senior, hands-on role for an independent contributor who ships fast and builds things right - clean architecture, simple design, code that's a pleasure to maintain.

• Build and refactor Java 21 / Spring Boot 3.x microservices powering agent execution, conversation state machines, and model orchestration
• Develop real-time, event-driven pipelines on Apache Kafka with low-latency requirements
• Design AI capabilities on top of our platform - vector search,  retrieval-augmented generation  (Qdrant)
• Integrate with multi-LLM providers (OpenAI, Anthropic, Google, Mistral) and AI frameworks (LangChain, LangGraph, Model Context Protocol)
• Write meaningful tests; enforce quality with static analysis and coverage tooling
• Diagnose production issues, drive systemic fixes, and raise the reliability bar
• Collaborate directly with AI engineers, frontend, QA, and product - you'll influence what gets built and how

• 7+ years in software engineering, 5+ in Java / Spring Boot
• Deep experience building distributed microservices with event-driven architectures (Kafka)
• Strong instinct for clean code - single responsibility, open-closed, dependency inversion aren't buzzwords to you, they're how you work
• Production experience with SQL and NoSQL databases
• Solid proficiency in modern Java (17+), concurrency, and reactive/event-streaming patterns
• Comfortable with Docker / Kubernetes and container-based deployment
• Clear, direct communicator who solves hard problems without overcomplicating them

Bonus: experience with vector databases (Qdrant, Pinecone), AI frameworks (LangChain, MCP), Python, S3, or functional languages

• Build core components of an AI-native enterprise platform.
• Work alongside AI experts and contribute to high-impact client solutions.
• Fast-paced, collaborative environment with room for growth.
• Early-stage equity package, with the opportunity to grow alongside the company.

Bucharest – hybrid or onsite