Effectiveness & Experimentation Director

dentsu; Greater London; Hybrid; GBP 60,000 - 80,000; Full time

Job summary

A global digital-first media agency is seeking a Global Experimentation Director to lead the design and implementation of testing programs for a major client, focusing on a culture of experimentation and continuous learning. This high-visibility role involves managing multi-market programs, implementing testing frameworks, and collaborating with analytics teams to derive actionable insights. The role offers a competitive salary and a hybrid working model from London or Manchester, fostering diversity and inclusion.

Benefits

Competitive salary

Tailorable benefits package

Flexible working arrangements

Qualifications

• Solid experience in media effectiveness experimentation or marketing analytics.
• Proven track record of managing multi-market experimentation programs.
• Deep understanding of testing methodologies and their applications.
• Strong program management skills to coordinate teams across markets.
• Experience designing knowledge-sharing systems.

Responsibilities

• Oversee global experimentation agenda and lead rollout of testing frameworks.
• Design and implement structured repeatable testing frameworks.
• Manage centralized experimentation programs across teams.
• Build scalable processes and tooling for test execution.
• Partner with media data to derive actionable insights.
• Translate complex outcomes into strategic media recommendations.
• Champion automation and knowledge-sharing initiatives.
• Drive education and change management across stakeholders.

Skills

Media effectiveness experimentation

Marketing analytics

Digital channels (SEO, PPC, Paid Social, Programmatic)

Program management

Knowledge-sharing systems

Measurement platforms (GA4, Meta Lift)

Analytical platforms (SQL, Power BI)

Job description

Job Description

Introduction

Dentsu is an integrated growth and transformation partner to the worlds leading organizations. Founded in 1901 in Tokyo Japan and now present in over 145 countries and regions it has a proven track record of nurturing and developing innovations combining the talents of its global network of leadership brands to develop impactful and integrated growth solutions for clients. Dentsu delivers end-to-end experience transformation (EX) by integrating its services across Media CXM and Creative while its business transformation (BX) mindset pushes the boundaries of transformation and sustainable growth for brands people and society.

iProspect is an important part of our world-class offering – a global digital-first end-to-end media agency. Its unmatched mix of media strategy and storytelling with digital expertise and audience knowledge defines the new territory of performance-driven brand building. By delivering human‑centric solutions iProspect accelerates growth for the worlds most iconic brands. The iProspect team works across a network of more than 8000 media and performance specialists spread across 93 global markets.

We're hiring a Global Experimentation Director to work from our office in London or Manchester.

Role Summary

We are hiring a Global Experimentation Director to lead the design implementation and governance of multi‑market testing programs for a globally recognized automotive client. Sitting within the iProspect Global Effectiveness team this role will focus on embedding a rigorous culture of experimentation across key markets, driving continuous learning, scalable automation and strategic insight into media investment decisions. You’ll work at the intersection of media data and analytics partnering with senior stakeholders and cross‑functional teams to deliver high‑impact experimentation frameworks that drive business outcomes.

Key Responsibilities

As Experimentation Director you will oversee the global experimentation agenda, lead the rollout of testing frameworks, champion best‑in‑class methodologies and enable local teams to execute, learn from and scale successful experiments. You will bring deep expertise in program management, measurement design and effectiveness automation paired with strong collaboration skills. This is a high‑visibility role designed for someone who thrives in complexity with a proven track record of delivering structured scalable effectiveness programs across multiple markets and teams.

• Lead the development and delivery of a global multi‑market experimentation roadmap aligned to business priorities and performance KPIs.
• Design and implement structured repeatable testing frameworks (e.g. A/B geo experiments, incrementality studies) that drive marketing effectiveness and decision‑making.
• Manage and scale centralized experimentation programs across regional and local teams, ensuring consistency, rigor and local enablement.
• Build scalable processes and tooling (e.g. experimentation libraries, knowledge hubs, dashboards) to support efficient test execution and insight sharing.
• Partner with media data and analytics stakeholders to define testable hypotheses, ensure statistical rigor and derive actionable insights.
• Work with Strategy & Planning teams on cross‑channel synthesis of experimental results, translating complex outcomes into strategic media recommendations.
• Champion automation and knowledge‑sharing initiatives to embed experimentation capabilities at scale.
• Drive education, training and change management across stakeholders to improve measurement fluency and experimentation maturity.

Skills / Qualifications

• Solid experience in media effectiveness experimentation or marketing analytics with hands‑on experience in at least one digital channel (SEO, PPC, Paid Social, Programmatic) within a global agency, consultancy or client environment.
• Proven track record of managing and scaling multi‑market experimentation programs that influence strategic media decisions.
• Deep understanding of testing methodologies (e.g. A/B, multivariate, geo‑testing, holdouts, incrementality, brand lifts) and when to apply them.
• Strong program management skills able to coordinate cross‑functional teams across markets and structurally deliver as well as communicate outcomes.
• Experience designing knowledge‑sharing systems (e.g. centralized testing repositories, playbooks, reporting dashboards).
• Competency with measurement platforms and tools (GA4, Meta Lift, DV360, MMM) and analytical platforms (SQL, Power BI, Looker Studio, R/Python).

What we offer

• This is a permanent role.
• The team is based from either Manchester or London and works on a hybrid basis.
• As well as a competitive salary you’ll enjoy a benefits package that you can tailor to your needs.

Inclusion and Diversity

At Dentsu we embrace diversity and inclusion, valuing the unique perspectives and contributions of every individual. We believe that diversity fuels creativity and innovation, benefiting our employees, partners and communities.

We welcome applications from all individuals regardless of race, ethnicity, nationality, religion, gender, gender identity, sexual orientation, age, disability, marital status or any other protected characteristic. Beyond recruitment we strive to create an environment where everyone feels respected, supported and empowered to bring their authentic selves to work.

We recognize the importance of work‑life balance and are open to discussing flexible working arrangements for all roles. If you need reasonable adjustments due to a disability or medical condition during our recruitment process, please contact us, quoting the reference number of the role that you are applying for. Your needs will be handled with respect and confidentiality to ensure an inclusive and accessible experience.

Experience Level

Director

Contract Information

Location: London

Brand: Global Iprospect

Time Type: Full time

Contract Type: Permanent