Senior Software Engineer

Overview

A subsidiary of Publicis Groupe, Epsilon is a leading provider of multi-channel marketing services, technologies, and database solutions. At Epsilon, we do more than collect and store data. We help some of the world's biggest brands discover real opportunities inside the data types, delimiters and decimals.

We're looking for an experienced Senior Software Engineer to help us build innovative and secure data solutions for social media, search, and digital ads within a Big Data environment. In this role, you will use best‑in‑class engineering approaches and secure data management practices to help process terabytes of data each week, while solving difficult problems using predictive analytics and innovative technologies.

• Design, develop, and maintain scalable backend services using Java and Python
• Apply spec‑driven AI‑assisted development as a core development practice, including:
  • Translating detailed functional and technical specifications into high‑quality code using AI tools
  • AI‑assisted code generation, refactoring, and optimization with strong human validation
  • Prompt‑driven development aligned to explicit design and acceptance criteria
  • Intelligent debugging, test generation, and code reviews using tools like Cursor, Claude Code, and Kiro
• Build and integrate RAG‑based solutions and Agentic AI workflows into enterprise systems
• Lead system design and architecture discussions
• Ensure high code quality through reviews, testing, and engineering best practices
• Collaborate with product, data, platform, and cross‑functional teams
• Own and resolve complex production issues.

• What you’ll bring with you:
  • Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field (or equivalent practical experience)
  • 7‑10 years of hands‑on software development experience
  • Strong expertise in Java and Python
  • Strong backend engineering experience with Java (e.g.,
    Spring or similar frameworks) and production‑grade service development
  • Experience with common Java build and delivery tooling (e.g.,
    Maven / Gradle) and source control workflows (e.g.,
    Git
    , pull requests)
  • Strong Data Modeling skills and experience with relational and NOSQL databases
  • Experienced working in Unix/Linux environments, including automation and scripting
  • Mandatory experience with spec‑driven AI‑assisted development
  • Practical, day‑to‑day usage of AI coding tools such as Cursor, Claude Code, and similar platforms
  • Ability to validate, refine, and product ionize AI‑generated code against explicit specifications
  • Mandatory hands‑on experience with:
    • RAG (Retrieval‑Augmented Generation) architectures
    • Agentic AI systems (tool‑using agents, orchestration, multi‑step reasoning workflows)
  • Strong fundamentals in:
    • Data Structures & Algorithms
    • Object‑Oriented Programming
    • Design Patterns & System Design
  • Experience building and operating backend systems in production
  • Solid understanding of REST APIs, microservices, and distributed systems
  • Proven ability to own problems end‑to‑end
    , including driving design, implementation, testing, and production support
  • Demonstrated technical leadership (mentoring junior engineers, raising code quality via reviews, ensuring implementations meet specifications and standards)
• Why you might stand out from other talent:
  • Frontend exposure using Angular or similar frameworks
  • Experience with Databricks, Spark
    , or large‑scale data processing
  • Experience with data modeling, data warehousing, and/or building ETL pipelines
  • Cloud platforms (
    AWS / Azure / GCP
    ) and Dev Ops practices
  • CI/CD pipelines, Docker, Kubernetes.

Base Salary: $88,900 - $165,100. Actual compensation within the range will be dependent upon, but not limited to, the individual's skills, experience, qualifications, location and applicable laws. The salary pay range is subject to change.

• 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 counseling

Epsilon is an Equal Opportunity Employer. Epsilon’s policy is not to discriminate against any applicant or employee based on protected characteristics. Epsilon also prohibits harassment and provides accommodations to applicants needing them.