Senior Developer

Overview

About Business Unit:

Powerful predictors of the future - our Analytics team seamlessly blends data science and business intelligence to provide unparalleled foresight for our platform offerings. They turn insights into actionable results for our clients by collaborating with senior team members and staying ahead of market trends, powered by our data assets. By using new-age analytic tools and emerging technologies, the team cultivates a dynamic learning environment for curious minds to thrive.

The Senior Developer is a builder. You will write the code behind our AI capabilities: agents, knowledge systems, and analytical applications used by analysts on live client work. This is a small team where the person who designs a component is usually the person who ships it, and where what you build reaches users in weeks rather than quarters.

We already run AI agents in production that generate analyst-grade SQL against our analytics environment. You will help extend that foundation into harder territory.

What You'll Build:

Interpretation. Systems that take the output of an analysis and produce business-relevant interpretation — what the numbers actually mean for a given client and category.

Client knowledge. A knowledge system that accumulates what the organization understands about each client and makes it retrievable by both people and agents.

Media Investment planning. Analytical tooling that supports budget allocation and media investment planning decisions.

Click here to view how Epsilon transforms marketing with 1 View, 1 Vision and 1 Voice.

Responsibilities

Building

• Design, build, test, and maintain the applications, agents, and automation that the Account Analytics organization runs on.
• Write clean, reviewed, documented code that another engineer can pick up and extend.
• Build integrations across data platforms, APIs, internal services, and reporting systems.
• Own components end to end — from design discussion through deployment and the support that follows it.

AI Engineering

• Implement LLM-based components: agents, tool interfaces, structured outputs, and the orchestration that connects them.
• Build and run the evaluation harnesses that tell us whether a change improved an agent or merely changed it. Non-deterministic systems need tests too, and building them is part of the job rather than an afterthought.
• Implement context and retrieval strategies, and contribute evidence to the decisions about which approach fits a given problem.
• Prototype quickly when a question is better answered by code than by discussion.

Collaboration

• Work with analysts and client teams to understand what a tool has to do before deciding how it will do it.
• Participate substantively in design and code review, as author and as reviewer.
• Contribute to the team's standards and to the documentation that makes them stick.

Qualifications

• 5+ years building and maintaining production software or data applications.
• Strong Python and SQL. You have worked in a real codebase with other engineers, not only in notebooks or scripts.
• Hands-on experience building with LLMs — prompting, tool use, agent frameworks, structured output — with something you shipped and can talk through in detail.
• Fluent with Git and collaborative development practice: branching, review, testing, deployment.
• Strong analytical and problem-solving ability, and the instinct to ask what a piece of output means rather than only whether the code ran.
• Clear written communication. Much of this team's collaboration happens in writing and across time zones.
• Bachelor's degree in Computer Science, Engineering, Data Science, Mathematics, Statistics, or a related discipline.

Additional Knowledge, Skills and Abilities

Preferred Technical Experience

• Agentic development environments — Claude Code, Cursor, GitHub Copilot, or similar — used as a daily working tool.
• Databricks, Greenplum or PostgreSQL, Snowflake, BigQuery, or comparable analytical platforms.
• Retrieval-augmented generation, embedding stores, and context management approaches.
• Cloud platforms (Azure, AWS, GCP) and CI/CD pipelines.
• Evaluation frameworks or testing approaches for LLM applications.
• Tableau, Power BI, or related visualization tools.
• Exposure to marketing measurement concepts — attribution, incrementality, campaign performance analysis. Useful, and learnable here if you are curious about it.

How You Work

• Strong ownership. You follow a problem through to the point where it stays solved.
• Genuine curiosity about emerging tooling, paired with judgment about when not to use it.
• Comfortable with ambiguity and with asking the questions that resolve it.
• Careful about quality without being precious about your first design.

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 with 1 View, 1 Vision and 1 Voice. 1 View of their universe of potential buyers. 1 Vision for engaging each individual. And 1 Voice to harmonize engagement across paid, owned and earned channels.

Epsilon’s comprehensive portfolio of capabilities across our suite of digital media, messaging and loyalty solutions bridge the divide between marketing and advertising technology. We process 400+ billion consumer actions each day using advanced AI and hold many patents of proprietary technology, including real-time modeling languages and consumer privacy advancements. Thanks to the work of every employee, Epsilon has been consistently recognized as industry-leading by Forrester, Adweek and the MRC. Epsilon is a global company with more than 9,000 employees around the world.

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.

Our values guide us to create value for our clients, our people and consumers.

• Act with integrity
• Work together to win together
• Innovate with purpose
• Respect all voices
• Empower with accountability

These pillars and values are our foundation—shaping our culture, guiding our decisions, and uniting us in common purpose.

Epsilon is an Equal Opportunity Employer. 
Epsilon is committed to promoting diversity, inclusion, and equal employment opportunities by using reasonable efforts to attract, recruit, engage and retain qualified individuals of all ethnicities and backgrounds, including, but not limited to, women, people of color, LGBTQ individuals, people with disabilities and any other underrepresented groups, traits or characteristics.