What We'll Need From You

• Deep expertise in Large Language Models (LLMs), including commercial and open-source models (e.g., OpenAI, Gemini, Claude, Llama), and selecting the right model for use case, cost, and performance constraints.
• Hands‑on experience building Gen AI applications using modern frameworks such as LangChain, LangGraph, LlamaIndex, and Hugging Face, including agentic and multi‑step workflows.
• Proven experience designing and implementing Retrieval‑Augmented Generation (RAG) systems, including vector databases (pgvector, Pinecone, Weaviate, FAISS, etc.) and advanced retrieval strategies (hybrid search, re‑ranking, metadata filtering).
• Strong understanding of prompt engineering, workflow design, and Gen‑AI optimization, balancing latency, cost, quality, and accuracy trade‑offs in production systems.
• Solid grounding in ML/DL concepts, with hands‑on experience applying frameworks such as PyTorch and/or TensorFlow, including embeddings and model fine‑tuning where appropriate.
• Experience deploying and operating production Gen AI systems, leveraging Docker, cloud‑native architecture, production APIs, and monitoring/observability tools, with an emphasis on reliability and scalability.
• Strong hands‑on software engineering skills, including Python, FastAPI, async programming patterns, and building high‑performance AI‑powered APIs.
• Understanding of AI system evaluation, safety, and governance, including hallucination handling, guardrails, feedback loops, and responsible AI considerations, combined with the ability to work independently and communicate effectively in agile environments.

What We Can Offer You

This role offers the opportunity to shape how Generative AI is responsibly adopted across critical enterprise workflows, influencing both technology strategy and business outcomes. You’ll work at the intersection of platform engineering, AI governance, and large‑scale transformation, with clear visibility and impact across the organization.

We work hard to have a positive financial and social impact on the communities we serve. In turn, we put our employees first and provide the best-in-class benefits they need to be well, live well and save well.

By joining Citi Belfast, you will not only be part of a business casual workplace with a hybrid working model (up to 2 days working at home per week), but also receive a competitive base salary (which is annually reviewed), and enjoy a whole host of additional benefits such as:

• Generous holiday allowance starting at 27 days plus bank holidays; increasing with tenure
• A discretional annual performance related bonus
• Private medical insurance packages to suit your personal circumstances
• Employee Assistance Program
• Pension Plan
• Paid Parental Leave
• Special discounts for employees, family, and friends
• Access to an array of learning and development resources

Alongside these benefits Citi is committed to ensuring our workplace is where everyone feels comfortable coming to work as their whole self every day. We want the best talent around the world to be energized to join us, motivated to stay, and empowered to thrive.

Sounds like Citi has everything you need? Then apply to discover the true extent of your capabilities.

Job Family Group:

Technology

Job Family:

Applications Development

Time Type:

Full time

Most Relevant Skills

Please see the requirements listed above.

Other Relevant Skills

For complementary skills, please see above and/or contact the recruiter.

Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.

If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity review Accessibility at Citi.

View Citi’s EEO Policy Statement and the Know Your Rights poster.