Senior AI Engineer

Who we Are: At Grant Thornton Greece, we're not just part of a global network of 76,000 professionals across 156 countries. We're independent thinkers who prioritize quality, inclusion, and integrity to create a better, more personal experience for our clients and our team. Our mission? To deliver expertise in a way that goes beyond — Personal, Proactive, and Agile. Great Place to Work certified for four years running. Best Workplaces Hellas for 2025 & 2026.

The role in detail: We are seeking a talented and experienced AI Engineer to join our AI Center of Excellence. This role involves developing and deploying state-of-the-art Generative AI solutions powered by Large Language Models (LLMs) and Agentic AI flows. You will collaborate with cross-functional teams to build secure, scalable, and high-performing AI systems that solve real-world problems using cutting-edge technologies. As part of the AI Center of Excellence, you will contribute to the creation of reusable GenAI components and frameworks, ensuring technical excellence, responsible AI practices, and continuous improvement.

The key responsibilities of this role will include:

• Write clean, scalable Python code applying strong OOP principles to build and integrate state-of-the-art Generative AI and Agentic AI solutions.
• Train and fine-tune LLMs using domain-specific datasets, and work with modern foundation models like GPT, Claude, Llama, and Mistral.
• Design and implement robust architectures, including Retrieval-Augmented Generation (RAG) pipelines, advanced chunking strategies, memory management, advanced prompt templating, Model Context Protocol (MCP), and context injection.
• Design and deploy sophisticated agent-based systems using frameworks such as LangGraph, LangChain agents, CrewAI, and AutoGen.
• Leverage industry-leading tools like LangChain, LlamaIndex, HuggingFace Transformers, and OpenAI APIs.
• Develop automated pipelines for model performance evaluation, bias detection, and Responsible AI compliance.
• Provide technical leadership, mentor junior engineers, and help shape our AI strategy.
• Collaborate closely with engineering and infrastructure teams for seamless deployment and continuous iteration.
• Produce clear, comprehensive documentation and reports for technical designs, project progress, and model performance.

To be successful at this role you need:

• Bachelor's degree in Computer Science, Information Technology, Software Engineering, or related field
• 3+ years of hands-on experience in AI/ML projects, building and delivering AI/GenAI applications
• Expertise and a deep understanding of the rapidly evolving Generative AI landscape, GenAI architectures, including RAG pipelines and model evaluation frameworks
• Expertise in LLM development, prompt engineering, vector-based retrieval techniques, and modern AI agent frameworks
• Strong command of Python with solid Object-Oriented Programming (OOP) principles, and experience with MLOps practices
• Familiarity with Responsible AI concepts, including fairness, transparency, Green AI and hallucination mitigation
• Strong problem-solving and critical thinking abilities

Bonus Qualifications (Nice to have):

• Experience in building or utilizing systems that conform to the Model Context Protocol (MCP)
• Experience with specific Azure AI services
• Open-source contributions
• Real-time/low-latency AI systems experience
• Cloud AI or ML certifications

Location: Athens, Athens_Andrianiou — Hybrid. AI Center of Excellence.

Benefits:

• Competitive salary and bonus
• Insurance program
• Fully funded training and professional qualifications
• Extra days off (August freedays, volunteering, early leave)
• Corporate sports teams
• Employee discounts
• Company car (level-dependent)

Milestones: Great Place to Work certified for four years running. Best Workplaces Hellas for 2025 & 2026. Best Workplaces for Women for three consecutive years. Best Workplace in Professional Services & Consulting for 2025 & 2026. Proud members of the Diversity Charter Greece and certified with the SHARE Equality Label.