Data Scientist

ExlService Holdings, Inc.; London; Hybrid; GBP 150,000 - 200,000; Full time

Job summary

A global data and AI company is seeking a Data Scientist with expertise in Generative AI. This role involves developing innovative solutions using Large Language Models (LLMs) to address business challenges. Candidates should have over 5 years of experience in data science, strong Python skills, and familiarity with tools like OpenAI and LangChain. The position offers a competitive salary, private healthcare, and a hybrid working model for a balanced lifestyle.

Benefits

Competitive salary

Private healthcare

Training and development opportunities

Flexible hybrid working model

Qualifications

• 5+ years of experience in Data Science / ML, with 1+ year hands-on in LLMs / GenAI.
• Strong background in machine learning and NLP.
• Experience with modern GenAI tools like OpenAI and Hugging Face.

Responsibilities

• Design and build Generative AI solutions using LLMs.
• Fine-tune foundation models using domain-specific data.
• Collaborate with teams to build end-to-end AI applications.

Skills

Python programming

Machine Learning

Natural Language Processing

Generative AI tools

Tools

Transformers

PyTorch

TensorFlow

LangChain

Job description

Job Description

EXL (NASDAQ: EXLS) is a global data and artificial intelligence ("AI") company that offers services and solutions to reinvent client business models, drive better outcomes and unlock growth with speed. EXL harnesses the power of data, AI, and deep industry knowledge to transform businesses, including the world's leading corporations in industries including insurance, healthcare, banking and financial services, media and retail, among others. EXL was founded in 1999 with the core values of innovation, collaboration, excellence, integrity and respect.

We are headquartered in New York and have more than 59,000 employees spanning six continents. For more information, visit www.exlservice.com.

Job Summary:
We are looking for a highly capable and innovative Data Scientist with experience in Generative AI to join our Data Science Team. You will lead the development and deployment of GenAI solutions, including LLM-based applications, prompt engineering, fine-tuning, embeddings, and retrieval-augmented generation (RAG) for enterprise use cases.
The ideal candidate has a strong foundation in machine learning and NLP, with hands-on experience in modern GenAI tools and frameworks such as OpenAI, LangChain, Hugging Face, Vertex AI, Bedrock, or similar.

Key Responsibilities:
• Design and build Generative AI solutions using Large Language Models (LLMs) for business problems across domains like customer service, document automation, summarization, and knowledge retrieval.
• Fine-tune or adapt foundation models using domain-specific data.
• Implement RAG pipelines, embedding models, vector databases (e.g., FAISS, Pinecone, ChromaDB).
• Collaborate with data engineers, MLOps, and product teams to build end-to-end AI applications and APIs.
• Develop custom prompts and prompt chains using tools like LangChain, LlamaIndex, PromptFlow, or custom frameworks.
• Evaluate model performance, mitigate bias, and optimize accuracy, latency, and cost.
• Stay up to date with the latest trends in LLMs, transformers, and GenAI architecture.

Required Skills:
• 5+ years of experience in Data Science / ML, with 1+ year hands-on in LLMs / GenAI projects.
• Strong Python programming skills, especially in libraries such as Transformers, LangChain, scikit-learn, PyTorch, or TensorFlow.
• Experience with OpenAI (GPT-4), Claude, Mistral, LLaMA, or similar models.
• Knowledge of vector search, embedding models (e.g., BERT, Sentence Transformers), and semantic search techniques.
• Ability to build scalable AI workflows and deploy them via APIs or web apps (e.g., FastAPI, Streamlit, Flask).
• Familiarity with cloud platforms (AWS/GCP/Azure) and MLOps best practices.
• Excellent communication skills with the ability to translate technical solutions into business impact.

Preferred Qualifications:
Experience with prompt tuning, few-shot learning, or LoRA-based fine-tuning.
Knowledge of data privacy and security considerations in GenAI applications.
Familiarity with enterprise architecture, SDLC, or building GenAI use cases in regulated domains (e.g., finance, insurance, healthcare).

As part of a leading global analytics and digital solutions company, you can look forward to:

• A competitive salary with private healthcare, critical illness life assurance at 4 x your annual salary, income protection insurance, and a rewarding pension.
• At EXL, we are committed to providing our employees with the tools and resources they need to succeed and excel in their careers. We offer a wide range of professional and personal development opportunities. We also support a range of learning initiatives that allow our employees to build on their existing skills and knowledge. From online courses to seminars and workshops, our employees have the opportunity to enhance their skills and stay up to date with the latest trends and technologies.
• As an Equal Opportunity Employer, EXL is committed to diversity. Our company does not discriminate based on race, religion, colour, national origin, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, age, or disability status.
• At EXL, we offer a flexible hybrid working model that allows employees to live a balanced, healthy lifestyle while strengthening our culture of collaboration.

To be considered for this role, you must already be eligible to work in the United Kingdom.