Principal Experimentation Consultant

This is Gain Ltd; City Of London; On-site; GBP 65,000 - 85,000; Full time

Job summary

A leading consultancy firm in London is seeking a Principal Consultant to lead client accounts and drive strategic experimentation initiatives. This role requires strong client relationship management skills and a proven track record in consultancy. The ideal candidate will mentor junior consultants and contribute to internal projects. Flexibility in working arrangements is provided with required office presence once a month.

Benefits

Bi-monthly office events

Professional development opportunities

Flexible working hours

Qualifications

• Proven experience in client consultancy and account management.
• Demonstrated ability to lead strategic experimentation programs.
• Strong background in data analysis and business strategy.

Responsibilities

• Lead a portfolio of clients and drive strategic experimentation.
• Mentor and develop junior consultants.
• Contribute to internal projects and methodologies.

Skills

Strategic thinking

Client relationship management

Commercial acumen

Mentoring

Education

Relevant degree or equivalent experience

Job description

Conversion is the world’s most trusted agency for data-driven decision-making, with teams across North America and EMEA. We help businesses solve complex challenges by using the best available evidence, combining experimentation & research to drive confident, high-impact decisions.

We work as strategic partners to our clients, applying a structured and rigorous approach to reduce uncertainty, optimise performance, and unlock growth. Our global team of specialists collaborates to deliver measurable business impact through data-led insights.

This role sits within the [UK team], working alongside our global counterparts to drive high-impact strategies for our clients.

As a Principal Consultant, you will be responsible for leading a portfolio of clients, driving strategic experimentation programs, ensuring commercial growth, and fostering long-term client relationships. You will take ownership of accounts strategy, revenue growth, and stakeholder engagement, ensuring experimentation delivers tangible business impact.

Internally, you will mentor and develop the Consultants within your portfolio, ensuring methodological excellence and commercial effectiveness. You will collaborate closely with the Senior Project Manager and other specialists to ensure seamless execution and portfolio success.

Beyond client work, you will contribute to the refinement of internal methodologies, support strategic decisions within the consultancy team, and play an active role in team development.

Additionally, you will collaborate with the wider business, supporting commercial growth by working with the Sales team on new opportunities and helping to shape the future direction of the consultancy function.

Portfolio strategic leadership

• Own and drive the strategic direction of client accounts, ensuring long-term program maturity and measurable impact.
• Define and pursue the long-term vision for experimentation within your portfolio, ensuring alignment with broader business objectives.
• Ensure frameworks in Conversion’s toolkit are properly and consistently used to structure experimentation programs effectively.
• Act as a trusted strategic advisor to senior client stakeholders, translating experimentation insights into broader commercial strategies.
• Work closely with the Senior Project Manager to ensure seamless portfolio execution, addressing roadblocks and maintaining operational excellence.
• Ensure experimentation insights are communicated effectively, translating results into compelling, persuasive, and commercially relevant narratives for stakeholders.
• Maintain a strong understanding of conversion drivers, including user research, data analytics, persuasion principles, and business context.

Portfolio commercial & account leadership

• Own and be accountable for the commercial success of your portfolio, ensuring renewals, upsells, and long-term client retention.
• Lead revenue growth and renewal planning, tracking renewal likelihood, identifying expansion opportunities, and ensuring account stability.
• Support the team in identifying and closing commercial opportunities, taking a leadership role in upsell discussions while empowering team members to execute where appropriate.
• Represent Conversion in high-level client engagements, building strong relationships with senior stakeholders to maintain trust and satisfaction.
• Act as the final decision-maker for key account-related decisions, ensuring alignment with client business goals.
• Proactively monitor client satisfaction, identifying risks early and implementing strategies to strengthen relationships.
• Take on accounts during critical phases (e.g., early onboarding or transition periods) and hand them over to the broader team when appropriate.

Mentorship, line management & team development

• Coach and mentor Senior Consultants and Consultants, ensuring they develop both technical expertise and commercial acumen.
• Maintain a strong understanding of team strengths and areas for development, ensuring continuous professional growth.
• Foster the development of Senior Consultants & Consultants by gradually increasing their ownership of accounts according to their skills, ensuring they have the support needed to succeed while maintaining overall portfolio oversight.
• Ensure high performance across the portfolio, proactively identifying development needs and providing structured feedback.
• Flag to leadership when additional support, training, or intervention is required for any team members within the portfolio.
• Enable team members to work on clients together happily, effectively, efficiently & professionally.
• Make informed promotion recommendations based on demonstrated growth, impact, and readiness for increased responsibility.

Thought leadership & internal projects

• Contribute to the evolution of experimentation methodologies, ensuring our approach remains best-in-class.
• Provide subject matter expertise in industry thought leadership, including blog content, case studies, and speaking engagements.
• Support internal knowledge-sharing, ensuring insights from across portfolios are leveraged for broader team development.
• Identify and support new product/service development, ensuring our offering remains competitive and aligned with market needs.
• Collaborate with product and delivery teams to enhance the efficiency and scalability of experimentation services.
• Consistently play an active role in team days, running sessions and contributing to discussions.
• Support the Director of Consultancy with hiring efforts when needed, providing input on candidate evaluation and ensuring alignment with team and business needs.
• Support Sales and Growth teams in pitches and business development efforts, providing strategic consultancy expertise to win new clients.

Office presence is required once per month for a company day, occasional company events, and may also be required for in-person client meetings from time to time.

We never request any form of payment or fees from candidates at any stage of the recruitment process. If you are contacted by anyone claiming to represent our company and asking for money or personal financial details, please report it immediate to [e-mail]. All genuine communication will come from official company channels.