Machine Learning Engineer, Ads Optimization & Ads Marketplace Quality

About the Role

As a Machine Learning Engineer, you will be part of a tight-knit team of engineers tackling complex, internet-scale problems at the core of Reddit's revenue engine. Your work will have a direct impact on the user experience, advertiser performance, and the overall efficiency of the ads marketplace. The team's efforts are centered around creating a balanced ecosystem where advertisers can achieve their goals while users have a positive experience with ads.

The Ads Optimization team focuses on the design and implementation of auction and bidding mechanisms, optimization systems for advertisers, and pacing strategies to ensure smooth budget allocation. On the other hand, the Ads Marketplace Quality team works on improving user experience with ads, combating ad blindness, and increasing valuable ad opportunities on the platform. Both teams play a vital role in Reddit's ads ecosystem, and as a Machine Learning Engineer, you will contribute to these efforts by developing and evolving the auction, bidding, and budgeting systems that power Reddit Ads.

What You Will Do

• Design and implement optimization algorithms for auctions, bidding strategies, and pacing that balance advertiser performance, user experience, and marketplace efficiency.
• Own systems end-to-end, from problem formulation and algorithm design to experimentation, production deployment, and ongoing iteration.
• Work across Ads Optimization and Ads Marketplace Quality to deliver measurable wins for advertisers and Redditors.
• Compute bids for different optimization objectives, such as CPC, CPA, and ROAS-based strategies.
• Pace budgets smoothly over time across accounts, campaigns, and ad groups, preventing overspend or underspend.
• Allocate spend and auction participation intelligently across segments, surfaces, and time zones.
• Translate product and marketplace goals into concrete optimization problems and constraints, such as ROI, revenue, delivery smoothness, fairness, and user experience.
• Collaborate with cross-functional teams, including Product, Data Science, and Infrastructure, to ensure the successful implementation of ads optimization and quality initiatives.
• Participate in the development of the technical roadmap for the ads optimization and marketplace quality systems, aligning with the company's overall strategy.

What We Are Looking For

• Strong background in machine learning, with a focus on optimization techniques and algorithms.
• Experience with the design and implementation of large-scale systems, preferably in an ads technology context.
• Proficiency in at least one programming language, such as Python, Java, or C++.
• Understanding of computer science fundamentals, including data structures, algorithms, and software design patterns.
• Experience with cloud-based technologies, such as AWS or Google Cloud.
• Strong analytical and problem-solving skills, with the ability to work on complex, open-ended problems.
• Excellent communication and collaboration skills, with the ability to work effectively with cross-functional teams.
• Experience with agile development methodologies and version control systems, such as Git.

Nice to Have

• Experience with deep learning frameworks, such as TensorFlow or PyTorch.
• Knowledge of natural language processing (NLP) or computer vision techniques.
• Familiarity with containerization technologies, such as Docker.
• Experience with workflow management tools, such as Airflow or Luigi.
• Participation in open-source projects or personal coding projects that demonstrate machine learning or software development skills.

Benefits and Perks

• Competitive salary and equity package.
• Comprehensive health, dental, and vision insurance.
• Generous paid time off (PTO) and holidays.
• Flexible working hours and remote work options.
• Access to professional development opportunities, including conferences, training, and workshops.
• Participation in Reddit's employee stock purchase plan.
• Reddit swag and other fun perks.
• Opportunities for career growth and advancement within the company.
• Collaborative and dynamic work environment with a team of talented professionals.

• Tip: When applying, make sure your resume and cover letter highlight specific experiences with machine learning algorithms, especially those related to optimization and bidding strategies.
• Showcase projects or contributions to open-source repositories that demonstrate your expertise in machine learning and software development.
• Prepare to discuss your understanding of auction mechanisms, pacing strategies, and how you would approach optimizing these systems for better advertiser and user outcomes.
• Be ready to walk through your process for designing and implementing optimization algorithms, including how you handle scalability and complexity.
• Consider reaching out to current or former Reddit employees for insights into the company culture and the day-to-day responsibilities of the role.
• When negotiating salary, consider not just the base pay but also the equity package and other benefits that contribute to your total compensation.