Theoretical Computer Science Internship Jobs in Illinois

Company Description
Overview
Epsilon's Decision Sciences Identity (DSI) team seeks a PhD-level Lead Research Scientist to advance the Identity Resolution Platform that powers real-time digital marketing at internet scale. You will contribute to research and development initiatives that expand identity capabilities across Epsilon's marketing businesses, transforming novel ideas into production technologies with measurable business impact.
This role sits at the core of Epsilon's identity platform, tackling complex, ambiguous problems using large-scale data. Working closely with engineering and product teams, you will apply analytical rigor, creativity, and strong computer science fundamentals to develop scalable identity solutions that improve marketing performance for leading brands.
Responsibilities

• Individually contribute to data science and machine learning R&D projects
• Use data science, machine learning, and/or computer science skills to conduct research and contribute to solutions to technology and business problems
• Contribute to projects from early-stage research through development
• Implement and optimize innovative algorithms in distributed environments
• Develop an understanding of Epsilon personalization platform and proprietary datasets
• Participate fully in our collaborative approach to research and applications projects

Qualifications
Qualifications

• Ph.D. in Computer Science, Electrical Engineering, Statistics, Mathematics, Economics, Physics, Chemistry, Operations Research, or related quantitative field
• Research experience and coursework in Machine Learning
• Strong understanding of statistical, analytical, and predictive modeling techniques
• Strong Python programming skills and experience with data structures, algorithms, and production-quality code development
• 2+ years of relevant programming experience through academic research, internships, or industry work
• Ability to code independently without AI as well as effectively leverage AI-assisted development tools
• Proven ability to design, execute, and deliver research projects
• Excellent communication and interpersonal skills, including ability to translate complex technical concepts for non-technical audiences
• Self-motivated, highly organized, and collaborative, with the ability to manage multiple priorities in highly collaborative, team-oriented environments

Additional, But Not Required Skills

• Experience with graphs/networks and unsupervised clustering algorithms (community detection on graphs)
• Experience working with large, complex datasets in research or production environments
• Experience with distributed computing and large-scale data processing (Spark, Hadoop, Databricks, cloud databases)
• Experience with cloud platforms and data ecosystems (AWS, S3, Databricks)
• Proficiency in SQL, Scala, Spark libraries, and advanced database querying
• Familiarity with LLMs, Generative AI, and agentic frameworks
• Experience in one or more advanced domains: Community Detection on Graphs, Unsupervised Learning, NLP, Information Retrieval, Mathematical Optimization, Control Theory, Time-Series Analysis, or Causal Inference
• Ability to partner with business and technical collaborators to deploy algorithms into production platforms
• Experience translating research innovations into scalable, customer-facing products
• Additional research experience in computational fields such as data science, AI/ML, statistics, computer science, or graph algorithms

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.
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Compensation Range: USD $87,100.00 - USD $173,700.00/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 8/31/2026.