Reddit

Senior Machine Learning Engineer, Ads Optimization

Reddit
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6 hours ago
Remote, United StatesSenior
H1B Sponsor

Base Salary

$217k - $303k/yr

Responsibilities

  • Design and implement models and policies for CPC, CPA, and ROAS-based bidding objectives.
  • Develop pacing systems that distribute campaign budgets smoothly while preventing overspend and underspend.
  • Allocate spend and auction participation across segments, surfaces, and time zones.
  • Translate marketplace and product goals into optimization problems and constraints involving ROI, revenue, delivery smoothness, fairness, and user experience.
  • Own systems from problem formulation and algorithm design through experimentation, production deployment, and ongoing iteration.
  • Lead complex or multi-quarter initiatives, set technical direction, and mentor other engineers while remaining hands-on.

Requirements

  • Have 3–5+ years of experience building, deploying, and operating machine learning systems in production; IC4 candidates typically have 5+ years.
  • Demonstrate strong programming skills in Python, Java, Go, or similar languages and solid software engineering fundamentals.
  • Have experience designing scalable data processing systems such as those using Spark, Kafka, Airflow, BigQuery, or Redis.
  • Translate ambiguous product or business problems into measurable solutions.
  • Demonstrate strong mathematics and optimization skills, with a degree or equivalent background in a quantitative field such as mathematics, physics, quantitative finance, economics, or operations research, or experience in optimization-heavy domains.
  • Implement custom optimization logic, including gradient-based methods and constraint handling, rather than relying solely on black-box tools.
  • Preferred qualifications include experience with advertising or auction systems, online marketplaces, search or ranking systems, bidding, pacing, budget optimization, auction or mechanism design, and campaign performance optimization.
  • Preferred qualifications include familiarity with large-scale real-time, low-latency decision systems; feature engineering; model optimization; production ML monitoring; cross-functional Ads or marketplace collaboration; and project leadership through rollout.
  • An advanced degree in Computer Science, Machine Learning, Operations Research, Applied Math, or a related quantitative field is preferred.

Benefits

  • Comprehensive healthcare benefits and income replacement programs.
  • 401(k) with employer match.
  • Global benefits supporting workspace, professional development, caregiving, and lifestyle needs.
  • Family planning support and gender-affirming care.
  • Mental health and coaching benefits.
  • Flexible vacation and paid volunteer time off.
  • Generous paid parental leave.
  • The role is a US-based position with a stated base salary range of $216,700–$303,400 USD, plus potential equity and, depending on the position, commission.
  • Interviews may be recorded, transcribed, and summarized by artificial intelligence, with an option to opt out before scheduled interviews.

Tech Stack

Apache AirflowApache KafkaApache SparkGoGoogle BigQueryJavaPythonRedis

Categories

Reddit

About Reddit

1,001-5,000 employees

Reddit is the heart of the internet, where millions of people get together to talk about any topic imaginable. Share, vote, and decide what matters in everything from breaking news, to fandoms, lifehacks, gaming, sports, health, and the internet’s cutest animals. With over 100,000 subreddit communities about every topic you could think of (and thousands more you couldn’t), whatever it is, there’s a place for you on Reddit. Interested in joining our growing team? Check out redditinc.com/careers.

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