Senior Client Integration Engineer

Our Senior Client Integration Engineers are experienced client‑facing digital technologists. You will become responsible for providing technical solutions and strategies to help our clients achieve their digital marketing objectives. This includes integrating new clients onto the Epsilon platforms, managing the technical relationship with existing clients, driving automation initiatives and providing technical sales support. An Epsilon Client Integration Engineer is a unique hybrid role within our company that combines aspects of a web technologist, business analyst and solutions architect. Our Client Integration Engineers leverage their technical capabilities, commercial acumen and knowledge of the Epsilon platform to design and deliver actionable strategies and solutions. Reporting in the Director Client Integration you will also have the opportunity to collaborate across Sales, Account Management, Media Delivery, Product and Engineering teams to produce high quality results serving as a subject matter expert or facilitator as needed. This is a hybrid role based in London.

What You’ll Achieve

• You will be developing scripts, maintaining database tables, and processing data feeds to support new client initiatives.
• Integrating our clients into the Epsilon system: designing, developing, implementing and testing technical solutions based on client and business requirements.
• Conceptualising integration strategies for complex, large‑scale clients whilst providing on‑going support & maintenance of existing clients.
• Identify and assist in developing enhancement opportunities and best practices across the enterprise through innovation, automation and knowledge sharing.
• Work with internal and external cross teams globally, including engineering, analytics, account management, product management and sales.
• Oversee troubleshooting issues impacting the team and drive them to resolution.

Who You Are

Ideally 3+ years' experience in a similar digital role.

What You’ll Bring With You

• Have a strong knowledge of digital ad tagging, tracking scripts & pixels, and measurement.
• Have experience with DSPs, familiar with Ad Servers & understand SSPs, CDPs, and DMPs.
• Have proven experience troubleshooting discrepancies in impression, click, and conversion data.
• Can identify and resolve ad delivery, tracking, and reporting issues.
• Have experience with UTM parameters, URL structures, and query strings for campaign tracking.
• Are familiar with programmatic buying and real‑time bidding (RTB) mechanics.
• Understands brand safety, viewability, and fraud detection technologies.
• Are passionate about problem‑solving and using their analytical side.
• Are inquisitive and need to know why we are doing whatever we are doing!
• Like to be organised – Time management and follow‑through skills are second nature.
• Possess excellent verbal and written communication skills and can tailor their communication style to the recipient.
• Have advanced coding experience in JavaScript, SQL, HTML.
• Love working in an energetic and engaging team environment.
• Are intrigued by the digital industry, have a good understanding of online tracking technologies and the digital marketing landscape.
• Have experience in a solutions architect / engineer or otherwise relevant technical role in AdTech or similar.
• Coding languages such as PHP, shell, python would be a nice to have.

Why You Might Stand Out from Other Talent

Bachelor's degree in computer science, Management Information Systems (MIS), or equivalent experience.

Additional Information

Epsilon is a global data, technology and services company that powers the marketing and advertising ecosystem. For decades, we’ve provided marketers from the world’s leading brands the data, technology and services they need to engage consumers.

Our pillars aren’t just words. They’re how we show up every day:

• People centricity: We focus on employee well‑being in an environment where colleagues truly care about each other.
• Collaboration: We work together, support one another, and collectively achieve goals.
• Growth: There are endless opportunities for growth through learning, development and career advancement.
• Innovation: We drive progress through cutting‑edge solutions and forward‑thinking approaches.
• Flexibility: We’ve created a balance between work and personal life, and we encourage adaptability to solve problems creatively.

As an Epsilon employee, you deserve perks and benefits that put you, your family and your finances first. Our benefits encompass a wide range of offerings, including but not limited to the following:

• Time to Recharge: Flexible time off (FTO), 15 paid holidays.
• Time to Recover: Paid sick time.
• Family Well‑Being: Parental / new child leave, childcare & elder care assistance, adoption assistance.
• Extra Perks: Comprehensive health coverage, 401(k), tuition assistance, commuter benefits, professional development, employee recognition, charitable donation matching, health coaching and counselling.

Epsilon is an Equal Opportunity Employer. Epsilon’s policy is not to discriminate against any applicant or employee based on actual or perceived race, age, sex or gender (including pregnancy), marital status, national origin, ancestry, citizenship status, mental or physical disability, religion, creed, colour, sexual orientation, gender identity or expression (including transgender status), veteran status, genetic information, or any other characteristic protected by applicable federal, state or local law.