Senior Staff Machine Learning Engineer, Search Platform

Reddit

64d • $266,000 - $372,400

About The Position

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. The Search Platform team at Reddit is the driving force behind our search backend, crafting and maintaining the essential services and databases that ensure users find what they’re looking for quickly and accurately. With a focus on building robust search infrastructure, we prioritize reliability and performance, enabling seamless search experiences across the platform. We are collaborating closely with a team of machine learning engineers and backend architects to develop the next generation of search infrastructure at Reddit, enabling a variety of search functionalities, including lexical and vector search.

Requirements

• 10+ years of experience in software engineering, specializing in cloud-native search and retrieval systems.
• 3+ years in technical leadership, architecting and scaling distributed systems in production environments.
• Deep expertise in lexical and vector retrieval technologies, such as Milvus, Vespa, and Elasticsearch, with strong knowledge of Lucene and Tantivy internals.
• Skilled in designing cloud-native architectures and managing containerized workloads using Kubernetes and AWS/GCP.
• Proven track record in building real-time data pipelines, indexing frameworks, and hybrid (lexical + vector) search architectures.
• Adept at translating complex technical challenges into clear, actionable strategies.
• Strong communicator and mentor who leads through collaboration, influence, and technical excellence.

Responsibilities

• Lead the design and development of Reddit’s next-generation search engine, powering lexical, embedding based retrieval and RAG frameworks at massive scale on a modern, cloud-native stack.
• Define the technical vision, drive architecture decisions, and mentor engineers to deliver an intelligent, reliable, and scalable search infrastructure.
• Lead the technical strategy, architecture, and implementation of Reddit’s next-generation search engine, integrating lexical, vector retrieval and Gen AI search applications.
• Partner closely with product engineers across Search, Feeds, Ads, Growth, and Safety to deliver high-quality, low-latency search and retrieval experiences.
• Define best practices for observability, reliability, and operational excellence in large-scale distributed systems.
• Mentor and guide engineers in designing scalable search infrastructure and adopting robust DevOps and SRE principles.
• Collaborate with infrastructure, and ML teams to ensure the search platform evolves to meet the needs of Reddit’s growing user base and diverse content ecosystem.

Benefits

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k Match
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Reddit Global Days off
• Generous paid Parental Leave
• Paid Volunteer time off

What This Job Offers

• Career Level: Senior
• Number of Employees: 1,001-5,000 employees