Machine Learning Engineer, Ads

Reddit is a community of communities. It's built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 116 million daily active unique visitors, Reddit is one of the internet's largest sources of information. For more information, visit

Reddit has a flexible workforce  If you happen to live close to one of our physical office locations our doors are open for you to come into the office as often as you'd like. Don't live near one of our offices? No worries: You can apply to work remotely in any country in which we have a physical presence.

We're evolving and continuing our mission to bring community, belonging, and empowerment to everyone in the world. Providing a delightful and relevant experience to our users applies to our Ads like all of our offerings, and we're excited to build a product that is best-in-class for our users and advertisers. The year ahead is a busy one

Team Description

Reddit is poised to rapidly innovate and grow like no other time in its history. We're currently hiring across multiple teams including: Ads Measurement Modeling, Ads Targeting & Retrieval, Advertiser Optimization and Ads Marketplace Teams.

Ads Measurement Modeling Team
This horizontal ML team in the Ads Measurement org works on proving the value of Reddit Ads to advertisers while ensuring privacy compliance. Their projects address challenges in signals, privacy, and identity, including Modeled Identity, Modeled Conversions, and enhancements for ATT opt-out utility.

Ads Targeting and Retrieval Team
This team designs and builds large-scale ML systems to improve targeting products. Their work spans offline and online retrieval systems that enhance contextual and behavioral targeting, helping advertisers reach the most relevant audiences.

Advertiser Optimization Team
This group consists of two horizontal teams focused on advertiser outcomes. The Recommendations and Forecasting team builds ML-driven tools for advertisers and sales, while the Bidding/Pacing team develops algorithms and customer-facing products like TCPA, TROAS, and performance advertising solutions. They work on marketplace dynamics, bidding and pacing innovations, and new advertiser tools.

Ads Marketplace Quality Team
This team improves the efficiency of Reddit's ads marketplace by developing algorithms for auction and pricing optimization, directly impacting advertiser and user value. They also contribute to strategic initiatives such as supply optimization and ad relevance, with the goal of showing the right ads to the right users at the right time and in the right context.

The Ads Creative Effectiveness Team
This team is a newly formed group aimed at improving ad creative at Reddit through generative and predictive products. We train, adapt and finetune LLMs/VLMs to help advertisers make impactful images, videos and text. We build performance predictors to understand and rank ad components, ensuring the advertiser ships the best possible campaigns. We construct insight and recommendation engines to guide advertisers towards best practices and key enhancements, distilling knowledge about what works at Reddit to supercharge their performance.This team is at the heart of Reddit's creative strategy, a core priority for the organization.

Role Description

Join the Ads team as a Machine Learning Engineer and become a key contributor to Reddit's business. In this hands-on role, you will be responsible for the full lifecycle of our ML systems, from initial research and modeling to deployment and optimization in production. Your work will directly impact how we deliver relevant ads and drive value for our advertisers across areas like ad ranking, bidding, measurement, and optimization.

Responsibilities:

• Design, build, and deploy industrial-level machine learning models to solve critical problems in ad ranking, bidding, and optimization.
• Take full ownership of the ML lifecycle, from ideation and research to building scalable serving systems and maintaining models in production.
• Perform systematic feature engineering to transform raw, diverse data into high-quality features that drive model performance.
• Work closely with product managers, data scientists, and engineers to translate business challenges into effective ML solutions.
• Improve the reliability and stability of our ML systems by building robust monitoring, alerting, and automated retraining pipelines.
• Research new algorithms, stay up-to-date with state-of-the-art ML techniques, and contribute to the team's strategy and roadmap.

Required Qualifications:

• At least 3+ years of end-to-end experience in training, evaluating, and deploying machine learning models in a production environment.
• Proficient in one or more general-purpose programming languages (e.g., Python, Scala) and have a solid understanding of software development best practices.
• Hands-on experience with a major machine learning framework (e.g., TensorFlow, PyTorch) and a deep understanding of core ML concepts and algorithms.
• Proven ability to work effectively with cross-functional teams, including product managers and data scientists, to translate business needs into technical solutions.
• Track record of using machine learning to drive key performance indicator (KPI) wins and solve complex, real-world problems.

Bonus Points:

• Experience working in the Ads domain 
• Experience or interest in the advertising business and understanding customer needs
• An advanced degree (MS/PhD) in a quantitative field.
• Familiarity with distributed systems and large-scale data processing technologies (e.g., Spark, Kafka).

Pay Transparency:

This job posting may span more than one career level.

In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit

To provide greater transparency to candidates, we share base pay ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below.

The base pay range for this position is:

$185,800 - $260,100 USD

In select roles and locations, the interviews will be recorded, transcribed and summarized by artificial intelligence (AI). You will have the opportunity to opt out of recording, transcription and summarization prior to any scheduled interviews.

During the interview, we will collect the following categories of personal information: Identifiers, Professional and Employment-Related Information, Sensory Information (audio/video recording), and any other categories of personal information you choose to share with us. We will use this information to evaluate your application for employment or an independent contractor role, as applicable.  We will not sell your personal information or disclose it to any third party for their marketing purposes.  We will delete any recording of your interview promptly after making a hiring decision.  For more information about how we will handle your personal information, including our retention of it, please refer to our Candidate Privacy Policy for Potential Employees and Contractors.

Reddit is proud to be an equal opportunity employer, and is committed to building a workforce representative of the diverse communities we serve.  Reddit is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If, due to a disability, you need an accommodation during the interview process, please let your recruiter know.

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