Lead Developer (Backend)

Company: Epsilon Strategy & Insights
Location: Schiller Park
Posted on: January 7, 2026

Job Description:

Epsilon is building the next-generation Retail Media Network (RMN) platform to power onsite advertising at scale; leveraging services from our industry-leading ad tech platform that already delivers billions of offsite ads across the open web. Our vision is a unified platform that seamlessly supports both onsite and offsite advertising with low latency, high throughput, and high reliability. We’re looking for a Lead Software Engineer to join our Core Platform Engineering team–a hands-on technical leader who can drive major initiatives end to end. You’ll design and build scalable backend services, guide technical decisions across teams, and mentor engineers to ensure we deliver resilient, high-performance systems. Ideal for those who thrive in accountable settings, blending planning with technical tasks, and enjoy crafting global systems. How You’ll Make an Impact • Lead the design and development of high-performance, distributed backend services for ad delivery and optimization. • Collaborate with product, platform, and operations teams to integrate new capabilities into the platform. • Improve system performance, fix production issues, and eradicate bottlenecks across the stack. • Partner with DevOps/SRE to evolve CI/CD, monitoring, and performance tuning. • Contribute to frontend integrations (SPAs, dashboards, tools) when needed, ensuring seamless workflows for internal and external users. • Mentor and guide other engineers through design reviews, code reviews, and technical planning. What You’ll Achieve • Provide critically important services that support a unified onsite/offsite ad serving platform. • Lead architectural improvements that reduce latency and increase throughput at scale. • Champion engineering best practices around design, testing, automation, and observability. • Influence the technical roadmap to ensure alignment between platform capabilities and business goals. Who You Are • Bachelor’s degree in Computer Science or related field (or equivalent experience). • 8 years of software engineering experience, with a strong focus on backend and distributed systems. • Deep expertise in Java and modern backend frameworks (Spring Boot or similar). • Experience with containerization and orchestration (Docker and Kubernetes). • Hands-on experience with streaming platforms (e.g., Kafka, Kinesis, Pulsar). • Strong knowledge of SQL and NoSQL databases, including schema design and query optimization. • Solid understanding of system architecture, data flow design, and API performance optimization. • Self-starter with demonstrated ability to lead initiatives with minimal oversight. Nice to Have • Experience in ad tech, especially in ad serving, RTB, or programmatic systems. • Familiarity with cloud-native environments (AWS, Kubernetes, Docker). • Experience with frontend technologies (TypeScript, React, or Angular). • Experience working with data engineering and analytics pipelines. Why Join Us 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. Base Salary: $98,000 - $182,000 Actual compensation within the range will be dependent upon, but not limited to the individual’s skills, experience, qualifications, location and application employment laws. The salary pay range is subject to change and may be modified at any time.

Keywords: Epsilon Strategy & Insights, Carol Stream , Lead Developer (Backend), IT / Software / Systems , Schiller Park, Illinois