Senior Software Engineer

Senior Software Engineer

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 are looking for a highly experienced Senior Software Engineer with 7+ years to design, build, and scale robust backend systems using Java and Python in an Agile environment. This role has a strong emphasis on spec-driven AI-assisted development, where engineers leverage clear technical specifications and modern AI coding tools such as Cursor, Claude Code, and Kiro to accelerate development while maintaining high engineering rigor and production quality. Join us and do some truly astounding things.

Responsibilities

• 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

Qualifications

• 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 productionize 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 and 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, and ensuring implementations meet specifications and standards)
• Experience working in Agile / Scrum teams

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 DevOps practices
• CI/CD pipelines, Docker, Kubernetes
• Observability, monitoring, and performance tuning experience

Epsilon operates in 30+ countries across EMEA, the Americas and APAC, with more than 8,000 employees. Check out a few of these resources to learn more about what makes Epsilon so EPIC:

Our Culture:

Life at Epsilon:

Epsilon has five values that define our culture and guide us as we create value for our clients, our people and consumers. We seek candidates who align with our company values, demonstrate them and make them meaningful in their day-to-day work:

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

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:

• Time to recharge: Flexible time off (FTO), 14 paid holidays, 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 benefits are subject to eligibility requirements and other terms. 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, color, 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. Epsilon also prohibits harassment of applicants and employees based on any of these protected categories. Epsilon will provide accommodations to applicants who need accommodations to complete the application process. Please reach out to View email address on click.appcast.io to request an accommodation. For San Francisco Bay and Los Angeles Areas: Epsilon will consider qualified applicants with criminal histories for employment in a manner consistent with the City of Los Angeles' Fair Chance Initiative for Hiring Ordinance and San Francisco Police Code Sections 4901-4919, commonly referred to as the San Francisco Fair Chance Ordinance. Applicants with criminal histories are welcome to apply.

Compensation Range: USD $88,900.00 - USD $165,100.00/Annually. This is the pay range the Company believes it will pay for this position at the time of this posting. Consistent with applicable law, compensation will be determined based on the skills, qualifications, and experience of the applicant along with the requirements of the position, and the Company reserves the right to modify this pay range at any time. Temporary roles may be eligible to participate in our freelancer/temporary employee medical plan through a third-party benefits administration system once certain criteria have been met. For regular roles, the Company will offer medical coverage, dental, vision, disability, 401k, and paid time off. The Company anticipates the application deadline for this job posting will be 9/30/2026.