Data Scientist

EXL; Greater London; On-site; GBP 90,000 - 135,000; Full time

Benefits offered by this job

Generous bonus

Private healthcare

Life assurance 4x salary

Income protection

Pension plan

ESPP

Cycle to work scheme

Professional development

Job summary

EXL is seeking a Data Scientist in London to lead GenAI initiatives, building LLM-based applications and RAG pipelines. You will fine-tune models, engineer prompts, and collaborate with data engineers and product teams to deliver enterprise AI solutions.

You should have a strong ML/NLP foundation, hands-on GenAI experience, and proficiency with leading tools and cloud platforms. A hybrid work model is supported with competitive compensation.

Qualifications

• 5+ years in Data Science / ML with hands-on GenAI / LLM projects.
• Strong Python and ML libraries including Transformers, LangChain, PyTorch or TensorFlow.
• Experience with OpenAI (GPT-4), Claude, Mistral, LLaMA or similar models.
• Knowledge of vector search, embedding models and semantic search techniques.
• Ability to deploy AI workflows via APIs or web apps (FastAPI, Streamlit, Flask).
• Familiarity with AWS/GCP/Azure and MLOps best practices.
• Excellent communication skills to translate technical solutions into business impact.

Responsibilities

• Design and build GenAI solutions with LLMs for business problems (customer service, automation, summarization).
• Fine-tune or adapt foundation models using domain data.
• Implement RAG pipelines and embedding models; manage vector databases.
• Collaborate with data engineers, MLOps, and product teams on end-to-end AI apps and APIs.
• Develop prompts and prompt chains using LangChain, LlamaIndex, PromptFlow, or custom frameworks.
• Evaluate model performance, mitigate bias, and optimize accuracy, latency, and cost.
• Stay current with trends in LLMs, transformers, and GenAI architectures.

Skills

Python

Transformers

LangChain

scikit-learn

PyTorch

TensorFlow

OpenAI GPT-4

Claude / Mistral / LLaMA

vector search

embedding models

semantic search

APIs / Web apps

FastAPI / Streamlit / Flask

Cloud platforms (AWS/GCP/Azure)

MLOps

communication

Tools

OpenAI API

LangChain

LlamaIndex

PromptFlow

Bedrock

Hugging Face

Vertex AI

FAISS

Pinecone

ChromaDB

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 60,000 employees spanning six continents. For more information, visit www.exlservice.com.

Role Title

Data Scientist

BU/Segment

Data Management

Location

London, United Kingdom (Flexible hybrid working)

Employment Type

Permanent

Summary of the role

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.

As part of your duties, you will be responsible for:

• 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.

Qualifications and experience we consider to be essential for the role

• 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.

Skills and Personal attributes we would like to have

• 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).
• Palantir Tool knowledge is preferred

As part of a leading global Data and AI company, you can look forward to

• A competitive salary with a generous bonus, private healthcare, critical illness life assurance at 4 x your annual salary, income protection insurance, and a rewarding pension.
• EXL provides everyday financial well-being solutions, such as cash back cards, in which you can earn cashback while enjoying discounts, promotions, and offers from top retailers. We also offer a Cycle Scheme where you can save money on bikes and cycling accessories.
• 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.
• EXL employees are eligible to purchase stock as part of our Employee Stock Purchase Plan (ESPP).
• 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.