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RedditStaff Machine Learning Engineer, Ads Foundational Representations
Reddit operates a massive online platform centered on millions of active communities where users share discussions, votes, and content daily. The organization seeks a Staff Machine…
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About This Role
Reddit operates a massive online platform centered on millions of active communities where users share discussions, votes, and content daily. The organization seeks a Staff Machine Learning Engineer to join the Ads Foundational Representations group in London. This team creates signals, core entity representations, and embeddings that capture semantic, behavioral, and contextual details for users, posts, and advertisements. This position splits roughly half its time between individual technical work like…
Job Description
Reddit operates a massive online platform centered on millions of active communities where users share discussions, votes, and content daily. The organization seeks a Staff Machine Learning Engineer to join the Ads Foundational Representations group in London. This team creates signals, core entity representations, and embeddings that capture semantic, behavioral, and contextual details for users, posts, and advertisements.
This position splits roughly half its time between individual technical work like modeling, data engineering, and automation, and half its time on technical leadership, strategy, and mentorship. Engineers in this role will guide multi-pillar technical directions, lead end-to-end projects from initial business gap analysis to final execution, and collaborate closely with product and data science groups.
Ideal candidates have extensive industry experience designing, deploying, and evaluating machine learning systems at scale, alongside demonstrated capability in leading cross-functional technical initiatives. The position suits professionals experienced in natural language processing, computer vision problems, and embedding-based solutions.
Reddit offers a hybrid working model permitting remote work from anywhere within the United Kingdom or the Netherlands for eligible locations. Total compensation details and exact salary figures are not specified in the job posting.
Responsibilities
- Mentor team machine learning engineers by reviewing designs and establishing analysis, engineering, and modeling best practices
- Partner with leadership to shape technical strategies for content-based embeddings and advertising relevance
- Build new embedding models or iterate on existing ones, covering sequence models, two-tower architectures, and aggregation pipelines
- Develop evaluation methodologies, prompt tune, fine-tune, and extract representations using local or third-party vision-language models and large language models
- Construct inference and data processing pipelines for developed models
- Conduct qualitative and quantitative evaluations, running end-to-end experiments across internal benchmarks, offline recommender system metrics, and online tests
- Implement automated testing, monitor performance, and enforce model management best practices to guarantee system reliability and scalability
- Participate in code and modeling reviews to maintain team performance and quality benchmarks
- Collaborate across functions to turn business requirements into technical solutions
Requirements
- At least 7 years of hands-on experience covering the complete lifecycle of industry-level model design, training, evaluation, testing, and deployment
- Demonstrated Staff-level technical leadership in mentoring engineers, raising standards, and driving complex cross-functional projects without direct authority
- Strong communication skills for conveying complex technical concepts in both written and verbal forms
- Extensive background working on content-rich natural language processing or computer vision problems at scale using embeddings
- Proven data-driven methodology for developing machine learning systems
- Familiarity with the ads domain, search systems, or recommender systems
- Practical experience using mainstream deep learning frameworks such as PyTorch or TensorFlow
Qualifications
- Experience with the company technology stack including Python, PyTorch, Airflow, BigQuery, Ray, Kubernetes, Kafka, and Google Cloud Platform
- Prior technical leadership experience mentoring junior engineers and directing complex projects
- Hands-on background in building, fine-tuning, or utilizing large language models
Core Skills
Benefits
- Global benefit programs covering workspaces, professional development, and caregiving support
- Family planning support and gender-affirming care
- Mental health and coaching benefits
- Private pension plan featuring employer matching
- Fully employer-sponsored group medical plan
- Income replacement programs
- Flexible vacation and paid volunteer time off
- Generous paid parental leave
Frequently Asked Questions
Where is this job located?
The role is based in London, but Reddit operates a flexible workforce allowing employees to work remotely from anywhere in the UK or the Netherlands.
What is the employment type?
The posting specifies a full-time employment type.
What salary does this position offer?
The job posting does not specify a salary.
What are the core experience requirements?
Applicants must have 7+ years of hands-on experience across the full lifecycle of industry-level machine learning models, demonstrated Staff-level technical leadership, and strong background in NLP or CV problems at scale using embeddings.
Sample Interview Questions
AI-generated questions tailored to this specific role — a preview of the full practice set.