Staff Machine Learning Engineer, Ads Content Understanding

3h•Remote

About The Position

Reddit is seeking a Staff Machine Learning Engineer to lead the Commercial Content Understanding roadmap for the Monetization organization. This role acts as the technical owner for Ads Content Understanding (ACU) signals and ML systems. The position requires a blend of technical leadership, mentorship, and hands-on work, focusing on driving designs, setting standards, and developing complex production systems. ACU is responsible for generating signals that describe Reddit content, assessing its brand safety and suitability, and understanding user intent in commercial contexts. Key areas include the Knowledge Graph, content taxonomies, opinion mining, and shopping/product understanding. The role will also involve managing a unified registry of ACU signals and driving the adoption of LLM and modern ML best practices within the team.

Requirements

7+ years of relevant MLE experience delivering production ML systems (models + pipelines + serving) at scale, ideally in large-scale content understanding domains, or Ads.
Demonstrated Staff-level technical leadership: has driven architecture decisions, standards, and design reviews across multiple teams, and has aligned PMs, DSs, and engineers on shared ML systems or platforms without direct people-management authority.
Excellent communication skills, with the ability to explain complex technical trade-offs to PMs, DSs, and other engineering teams, especially in ambiguous, cross-team problem spaces like Seekers/Searchers monetization.
Strong track record building and shipping NLP / Language models / content understanding models to production (e.g., classifiers, encoders, sequence or session models), with clear business outcomes (e.g., CTR/ROAS uplift, safety improvements).
Experience with commercial or intent modeling is a strong plus.
Practical experience using LLMs in production for labeling, evaluation, or distillation (e.g., LM-as-judge, prompt-based classifiers, LLM-generated labels distilled into smaller models), including managing quality, cost, and latency trade-offs.
Deep experience with PyTorch, TensorFlow, or similar, and production-quality code in Python (and ideally one statically typed language like Go/Java/C++).
Comfortable owning training, evaluation, and deployment code end-to-end.
Experience designing ML systems and pipelines: offline training, feature pipelines (batch/streaming), online serving, monitoring, and experimentation for high-traffic surfaces.

Responsibilities

Provide technical leadership and mentorship to MLEs and SWEs in ACU, acting as the de facto tech lead for content understanding and signals.
Drive design reviews, set technical standards, and uplift the team’s modeling and systems craft.
Develop evaluation systems and quality monitoring systems for content understanding signals using SOTA LM-judge practices.
Drive operational excellence for ACU’s ML systems by defining SLOs, alerting, and dashboards for key signals (coverage, latency, precision/recall, cost).
Build and evolve content understanding capabilities for commercial conversations (e.g., reviews vs. recommendations vs. comparisons vs. Q&A; sentiment and stance; product entities and categories) and operationalize them as robust signals.
Lead design and implementation of signals pipelines and produce an ACU signals registry.
Partner with platform teams and other content understanding teams to ensure efficient, reliable serving at Reddit scale.
Drive LLM and modern ML best practices within ACU, defining when to prompt, finetune, or distill, and designing evaluation and safety harnesses.
Lead at least one major distillation effort to replace external APIs with in-house models.
Operate across the full ML lifecycle (problem framing, data, modeling, evaluation, deployment, monitoring, and oncall).
Design scalable, resilient MLOps pipelines and champion responsible AI (bias, safety, explainability) for ACU’s models and signals in production.

Benefits

Comprehensive Healthcare Benefits and Income Replacement Programs
401k with Employer Match
Global Benefit programs that fit your lifestyle, from workspace to professional development to caregiving support
Family Planning Support
Gender-Affirming Care
Mental Health & Coaching Benefits
Flexible Vacation & Paid Volunteer Time Off
Generous Paid Parental Leave
Equity in the form of restricted stock units
Commission (depending on the position offered)
Medical, dental, and vision insurance
Generous time off for vacation
Parental leave