Principal Software Engineer, Ads Backend Engineering

Details

Reddit's Ads Foundations org combines Ads Engineering, Product, ML Systems, and Experimentation to deliver the best ads to Reddit users. The team focuses on evolving the Ads and Reddit tech stacks, balancing advertiser and user needs, improving engineering velocity and happiness, standardizing cloud resources and data observability, and driving cost-of-revenue tracking and optimizations. The Ads Infrastructure team validates engineering excellence for systems serving millions of customers.

Responsibilities

• Define and drive long-term technical architecture and platform strategy for Reddit Ads backend systems (3–5+ year horizon).
• Identify foundational gaps and lead strategic investments across Ads infrastructure.
• Architect systems that power billions of ad impressions with high reliability, low latency, and cost efficiency.
• Set standards for system design, scalability, and operational excellence across Reddit engineering.
• Lead cross-org and cross-functional technical initiatives that span beyond Ads, partnering with Infrastructure, Data, Machine Learning, and Product teams.
• Champion rigorous observability, reliability engineering, and cost-aware architecture practices across the Ads organization.
• Coach, sponsor, and elevate Staff and Senior Engineers; model a culture of technical curiosity, deep ownership, and high standards.
• Represent Reddit’s technical brand externally through talks, blog posts, patents, or open source contributions and stay ahead of industry trends in large-scale distributed systems, ads infrastructure, and backend engineering.

Requirements

• 10+ years of experience designing and operating highly scalable backend infrastructure.
• Recognized technical leader with a proven track record of driving large-scale platform transformations.
• Deep expertise in distributed systems, backend architecture, infrastructure, and performance engineering.
• Skilled at driving clarity in ambiguous spaces and influencing technical strategy across organizations.
• Exceptional collaboration and communication skills with the ability to align technical vision with business outcomes.
• Expertise in one or more general-purpose programming languages: Python, Go, Java, Rust, or C++.
• Strong experience with systems observability, reliability, and operational best practices.

Bonus (preferred)

• Experience in AdTech, real-time bidding systems, or creative management platforms.
• Experience driving infrastructure cost efficiency and performance optimization at scale.
• Contributions to technical communities or industry research.
• Prior experience with Technical Program Management for multi-year infrastructure efforts.

Benefits

• Comprehensive healthcare benefits and income replacement programs.
• 401(k) match.
• Family planning support and gender-affirming care.
• Mental health and coaching benefits.
• Flexible vacation & Reddit Global Days Off; generous paid parental leave; paid volunteer time off.
• Eligible for equity in the form of restricted stock units; some roles may be eligible for commission.

Pay Transparency

• Base pay range for US-based applicants: $260,800 - $365,100 USD.
• Final offers vary based on skills, experience, and other factors.

Other Notes

• Role is the most senior individual contributor position within the Ads Foundations organization, expected to drive technical strategy, organizational influence, and external thought leadership.