Senior Software Engineer

Senior Software Engineer Epsilon is building the next generation Retail Media Network (RMN) platform to power onsite advertising at scale, leveraging services from our industry-leading platform that already serves billions of offsite ads across the open web. Our vision is a unified platform for both onsite and offsite ads, delivering low-latency, high-throughput performance across the board. We're looking for a Senior Software Engineer to join our Core Platform Engineering team, someone with a self-starter mindset who thrives with minimal direction, can quickly grasp business and technical goals, and takes ownership from concept through delivery. This is a high-impact role where you'll shape the architecture, optimize performance, and ensure our systems are built for scale, reliability, and innovation. You'll be at the forefront of building a next-generation advertising platform that combines the speed and sophistication of programmatic ad serving with the personalization and commerce power of retail media. Your work will directly shape how millions of users experience advertising across top retailers and brands. Responsibilities: Design, implement, and maintain high-performance, low-latency services for advertising. Collaborate with product, platform, and operations teams to integrate new capabilities into the platform. Optimize system performance, fix production issues, and eliminate bottlenecks across the stack. Contribute to frontend integrations (SPAs, dashboards, tools) when needed, ensuring seamless workflows for internal and external users. Partner with data engineering teams to design and integrate event tracking, analytics, and reporting pipelines. Champion code quality, testing standard processes, and CI/CD automation. Deliver mission-critical enhancements enabling fast, accurate, and scalable ad delivery. Build robust, future-proof services and interfaces that empower rapid feature development. Improve system observability, monitoring, and fault tolerance. Qualifications: Bachelor's degree in Computer Science or related field (or equivalent experience). 6+ years of experience in backend and/or full stack software development. Strong backend expertise in Java, with experience in high-performance, distributed systems. Experience with streaming platforms (e.g., Kafka, Kinesis, Pulsar). Proficiency with relational databases (SQL) and NoSQL data stores. Understanding of low-latency, high-throughput architectures and clean software design principles. Experience building SPAs with TypeScript and modern frameworks (Angular, React, or similar). Why you might stand out from other talent: Master's degree or 10+ years software engineering experience. Experience in ad tech, especially ad serving, RTB, or programmatic platforms. Familiarity with cloud-native environments (AWS, Kubernetes, Docker). Experience with large-scale event tracking, data pipelines. Because You Matter: 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 11/6/2026. Digitas