Staff Machine Learning Engineer, Developer Platform

Reddit is a community of communities, home to open and authentic conversations on the internet. The Staff Machine Learning Engineer will build ranking and personalization systems to connect users with apps and games on Reddit, collaborating with cross-functional teams to design and implement best-in-class solutions.

Responsibilities:

• Design and ship the next generation ranking and ML backend systems that power discovery of Dev Platform apps and games across Reddit surfaces
• Partner with ML, DS, and product to define signals, APIs, and feedback loops for training, deploying, and iterating on ranking models
• Explore and productionize new retrieval, ranking, and experimentation approaches that unlock new Dev Platform experiences
• Champion reliability, observability, and experimentation best practices for ranking systems
• Write efficient, scalable code in our Go / Python / Baseplate / GraphQL stack
• Mentor engineers and lead technical discussions, shaping the long-term ranking and personalization strategy for Dev Platform

Requirements:

• 8+ years of experience as a software engineer building large-scale distributed systems and/or data-intensive, ML-driven systems, using Go, Python, C++, or another object-oriented language
• Proven track record working on cross-functional product teams (PM, Design, DS, Eng) where you owned end-user outcomes, not just models or infra, and shipped features that moved core product metrics
• Experience designing and improving ML tooling and platforms: deployment and rollout, automation, experiment frameworks, system diagnosis, reproducibility, and ML monitoring/alerting
• Experience designing and implementing performant, stable, and efficient ML or ranking systems (recommendation, ads, search, feed, or similar high-throughput decision systems)
• Strong organizational skills with the ability to prioritize, sequence, and de-risk work, keeping complex projects on schedule with a high attention to detail
• BS in Computer Science or a related technical field, or equivalent practical experience
• Comfortable with software engineering best practices: testing, code reviews, technical design docs, and clear documentation for other teams that depend on your systems
• Entrepreneurial mindset: you are self-directed, comfortable in ambiguity, and biased toward action in fast-paced environments. You like 0→1 building, iteration, and learning from experiments and failures
• Excellent communication skills: you collaborate effectively in a remote, cross-functional team, and can explain complex ML and ranking concepts to both technical and non-technical stakeholders