Senior AI Engineer With Reactjs

EPAM SYSTEMS TURKEY YAZILIM GELİŞTİRME LİMİTED ŞİRKETİ

We are seeking a Senior AI Engineer with strong expertise in ReactJS and Python to join our team and help build, debug, and scale intelligent applications powered by LLMs and agent-based architectures. The ideal candidate combines deep backend engineering skills with a sharp eye for frontend quality and thrives on tracing complex issues across the full stack — from UI rendering to agent reasoning failures.

Responsibilities

• Design and build async endpoints, background tasks, and streaming responses using Python and FastAPI.
• Develop and maintain agent-based systems, including prompt design, tool-calling, and RAG pipelines.
• Diagnose and resolve LLM failure modes such as hallucination, context contamination, and non-deterministic output.
• Tune retrieval quality through chunking strategies, embeddings, and vector search optimization.
• Build and fix production-grade React UIs, including layout, responsive behavior, and streaming state management.
• Identify and resolve concurrency issues, including shared mutable state and callback bleed under concurrent requests.
• Operate within Docker and Kubernetes environments, including deployment and pod/log debugging.
• Write and maintain test coverage using pytest and vitest, including mocks and fixtures.
• Trace symptoms to root causes across frontend, backend, and agent layers to ensure system reliability.

Requirements

• 5+ years of experience with Python, FastAPI, and asynchronous programming patterns.
• Proficiency in agent frameworks such as pydantic-ai, LangGraph, or LangChain, with hands-on experience in prompt engineering and tool-calling.
• Expertise in RAG systems, including chunking, embeddings, and vector search tools such as Qdrant or pgvector.
• Skills in React (hooks) and CSS, with the ability to build and troubleshoot complex, responsive UIs.
• Understanding of concurrency and state management, with experience implementing request-scoped state, locks, and thread-safety.
• Familiarity with Docker and Kubernetes, including container management and deployment debugging.
• Background in testing practices using pytest and vitest, with consistent use of mocks and fixtures.
• Strong debugging skills with the ability to trace issues across frontend, backend, and agent layers.
• English proficiency at B2 level or higher.

Nice to have

• Experience with AWS Bedrock or other model gateway platforms beyond OpenAI.
• Familiarity with Langfuse or other LLM observability tooling.
• Knowledge of python-pptx or document generation tools for PowerPoint and PDF outputs.
• Background in regulated industries such as pharma or life sciences, including familiarity with FDA PMA/510(k) and IVDR terminology.
• Skills in Helm chart authoring and CI/CD pipelines using GitHub Actions.
• Design sensibility for building premium, non-generic user interfaces.
• Experience integrating SSO/OAuth solutions such as Azure AD or MSAL.
• Familiarity with vector DB operations, including Qdrant collection management and embedding pipeline maintenance.
• Understanding of prompt-eval or LLM-testing frameworks for measuring answer quality over time.