Senior Data Scientist

We are looking for a Senior Data Scientist to lead the design and delivery of machine learning, statistical modelling and experimentation solutions that solve complex business problems and drive measurable outcomes across our client base. You will combine hands‑on technical expertise with strong consulting and stakeholder skills, shaping analytical approaches, guiding delivery and translating data into clear, actionable insight.

Optima Partners is a fast‑growing professional services firm helping leading organisations transform customer engagement at the intersection of marketing, technology and data. We work with major brands including Lloyds Banking Group, Nat West, Nationwide, Aviva, Virgin Media O2, BT, Centrica, and GSK. As we scale from 80 to 200 people we’re growing our Advanced Data team. We are collaborative, curious and focused on delivering practical insight that helps organisations make better decisions and grow sustainably.

You will join a practitioner‑led business with a strong data science community, working alongside people who are passionate about applying analytical thinking to real‑world business problems.

As a Senior Data Scientist, you will be a technical lead responsible for shaping, developing and implementing machine learning and statistical solutions that deliver meaningful value for our clients. You will work closely with senior stakeholders to understand business challenges, define analytical strategies, oversee delivery and turn complex outputs into clear, actionable recommendations. This is a great opportunity for an experienced data scientist to take ownership of high‑impact work across multiple commercial sectors, contribute to multi‐disciplinary project teams and play a visible role in growing and developing our data science practice.

• Leading the development and implementation of machine learning and statistical models to solve practical, high‑value business problems
• Partnering with senior stakeholders to understand objectives, shape analytical approaches, influence decisions and communicate findings effectively
• Translating complex technical outputs into clear, transparent and actionable recommendations that support strategic decision‑making
• Exploring data, testing hypotheses and identifying opportunities to create customer, operational and commercial value
• Collaborating with and guiding teams across data science, engineering, strategy and design to deliver high‑quality outcomes
• Championing emerging data science techniques, including practical applications of Large Language Models, and helping translate them into client‑ready solutions
• Mentoring junior colleagues, reviewing analytical work and contributing to the development of best practice within the Advanced Data team

• Strong academic background in mathematics, statistics, science, engineering or another numerate discipline
• Minimum 2:1 degree in a STEM subject, with a postgraduate qualification in a quantitative field considered beneficial
• Deep knowledge of statistics, including experimental design, uncertainty quantification, causal inference and predictive modelling
• Significant experience applying supervised and unsupervised machine learning techniques in commercial or client‑facing environments
• Advanced proficiency in Python and/or R, with experience ope rationalising data science solutions and working with modern data science tooling
• Excellent communication skills, with the ability to explain complex analysis clearly and confidently to technical and non‑technical audiences
• Strong problem‑solving skills, commercial curiosity and the ability to lead work independently while supporting others in small, high‑performing teams
• Strong understanding of commercial value drivers such as revenue, cost, profitability, customer behaviour and operational performance
• Experience mentoring junior data scientists,…