Principal Engineer - Ads Signals, Identity & Measurement

About Reddit

Reddit is seeking a highly skilled Principal Engineer to join the Ads Signals, Identity & Measurement team. This role focuses on building scalable systems that power ad signals, identity resolution, and measurement across Reddit’s advertising ecosystem.

Role

As a Principal Engineer, you will design, implement, and scale critical services that process vast amounts of advertising data, drive identity reconciliation across devices, and deliver accurate measurement and attribution. You will collaborate with Ads Tech, Data Platform, and Product teams to improve targeting, measurement accuracy, and privacy-preserving analytics at scale.

Responsibilities

• Design, implement, and scale high-availability services handling billions of events per day.
• Build robust identity resolution and user-level signals across devices and platforms.
• Develop measurement instrumentation for ad performance, attribution, viewability, and CTR/conversion tracking.
• Collaborate with cross-functional teams to define technical strategy, architecture, and data models.
• Mentor engineers and contribute to the growth of the Ads Signals engineering team.

Qualifications

• 8+ years of hands-on software engineering experience, preferably in ads tech, ML systems, or identity-related domains.
• Strong proficiency in Python, Java, Scala, or Go.
• Experience with distributed systems, data processing pipelines, streaming, and storage systems.
• Deep knowledge of machine learning techniques and their application to signals and attribution.
• Excellent communication and collaboration skills; ability to influence technical strategy.
• BS/MS/PhD in Computer Science or related field.

Benefits & Environment

Competitive compensation, comprehensive benefits, and a remote-friendly culture with opportunities to impact millions of users globally. Reddit supports work-life balance, professional growth, and inclusive collaboration.