Senior software developer Jobs in Chicago, IL

Overview
How You'll Make an Impact
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
What You'll Achieve

• 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
What You'll Bring with you:

• 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.

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

Additional Information
When You Join Us, We'll Create Something EPIC Together
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.

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 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 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 needing accommodations to complete the application process. Please reach out to LeaveofAbsence@epsilon.com to request an accommodation.

For San Francisco Bay and Los Angeles Areas: Epsilon will consider for employment qualified applicants with criminal histories 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.

#LI-KM1



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. Temporary roles may also qualify for participation in our 401(k) plan after eligibility 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 8/20/2026.