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Reddit

Senior Machine Learning Engineer, Ads Contextual Intelligence

Job Summary

Reddit is seeking a Senior Machine Learning Engineer to develop and deploy NLP models for content understanding within its Ads Contextual Intelligence team. The role involves building data pipelines, improving classification and embedding models, and integrating signals into advertising systems like targeting and ranking. Candidates should have extensive experience with NLP, deep learning frameworks such as TensorFlow or PyTorch, and full model lifecycle management. The position offers an opportunity to work on large-scale data at Reddit, with a focus on marketplace efficiency, safety, and providing valuable business insights.

Required Skills

Python
Machine Learning
Model Testing
Model Evaluation
Natural Language Processing
Team Collaboration
Airflow
Deep Learning Frameworks
Leadership
PyTorch
TensorFlow
Model Deployment
Model Monitoring
Kubernetes
Golang
Kafka
Cloud Platforms
BigQuery
Data Processing Pipelines
APIs Development
NLP Models
Ray
Model Management

Benefits

Flexible Vacation
Family Planning Support
Gender-Affirming Care
Income Replacement Programs
Mental Health & Coaching Benefits
Group Personal Pension Scheme
Bike to Work Scheme
Reddit Global Days Off
Private Medical Scheme
Dental Scheme

Job Description

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 101M+ daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit redditinc.com.

Reddit has a flexible first workforce! if you happen to live close to our physical office location 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 from the Netherlands or the United Kingdom.

The Ads Contextual Intelligence (ACI) team is responsible for all the “contextualization” projects within the Reddit Monetization charter. We are in charge of making sense of all user and advertiser-generated content in an automated fashion at scale, providing the right combination of signals to improve marketplace efficiency and bringing to the surface Business Intelligence insights. Our team has the potential to highlight one of Reddit's biggest differentiators: genuinely curated, high-quality, extremely relevant, and daily updated organic content. We are a Machine Learning/Data heavy team with a focus in the following areas:

  • Contextual Signals & Relevance - Make sense of organic (posts, comments, subreddits) and promoted (ads, shopping products, their landing pages) content via classification into interpretable tags and embedding into a shared space.
  • Safety & Suitability - Build in-house classification capabilities for the detection of sensitive & unsafe content in Reddit content to ensure Brand Safety and suitability of ads for users.
  • Knowledge Graph - Semi-automatic curation, expansion, and utilization of Reddit very own Knowledge database. NLP tokenization, NER models, disambiguation systems at KG node level.
  • Marketplace Efficiency - Helping Targeting, Retrieval, Ranking, and Marketplace Quality deliver best-in-class performance leveraging our Contextual Signals
  • Business Intelligence Applications - Bring Contextual Signals (Web, APIs, Custom Reporting) to Advertisers and other businesses to empower a new generation of Business Intelligence and help Brands understand Reddit bette

As a Senior ML Engineer, you’ll be in charge of the full cycle execution of content understanding projects - from collaborating with cross-functional teams on requirements and design to the implementation to the experimentation.

Responsibilities

  • Developing new or iterating on existing NLP algorithms and models for advertising use cases, such as NER, text classification, text embedding models, etc.
  • Building data processing pipelines & APIs that make the signals and annotations computed with those models available.
  • Hands-on help and consulting for the integration of contextual signals into downstream optimization models (Ad Targeting, Ad Ranking, etc.).
  • Ensuring the reliability, scalability, and performance of the ML systems by writing automated tests, monitoring performance, and implementing best practices for model management.
  • Participating in modeling and coding reviews: You will review work by other team members and provide feedback to ensure that it meets the team's standards for quality and performance.
  • Collaborating with cross-functional teams to understand business requirements and translate them into technical solutions.

Required Qualifications:

  • 5+ years of hands-on experience with the full lifecycle of designing, training, evaluating, testing, and deploying industry-level models.
  • Experience building NLP models and integrating them at scale.
  • Experience with mainstream DL frameworks: TensorFlow or PyTorch.
  • Excitement about working with data and readiness to look behind the metric numbers.

Preferred Qualifications:

  • Tech leadership experience: mentoring junior engineers and leading complex projects.
  • Experience with our stack (Python, Golang, Airflow, BigQuery, Ray, k8s, kafka, GCP/AWS)
  • Familiarity with the Ads domain and/or Search/Recommender systems is a strong plus.
  • Hands-on experience with using/fine-tuning/building LLMs.

Benefits:

  • Group Personal Pension Scheme with Employer match
  • Private Medical and Dental Scheme
  • Income Replacement Programs
  • Family Planning Support
  • Gender-Affirming Care
  • Mental Health & Coaching Benefits
  • Bike to Work scheme
  • Flexible Vacation & Reddit Global Days Off

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.

Interested in this job?

Application deadline: Open until filled

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Reddit

A social media platform where users create and participate in communities (subreddits) to discuss a wide range of topics, share content, and connect.

See more jobs
Date PostedMay 31st, 2025
Job TypeFull Time
LocationRemote - United Kingdom
SalaryCompetitive rates
Exciting remote opportunity (requires residency in United Kingdom) for a Senior Machine Learning Engineer, Ads Contextual Intelligence at Reddit. Offering competitive salary (full time). Explore more remote jobs on FlexHired!

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