Machine Learning Engineer, Answers Relevance

At Reddit, machine learning sits at the heart of how millions of people discover, connect, and engage with the world’s largest collection of human conversations. From “How do I fix a leaky faucet?” to “What should I watch next?”, the Answers Relevance team leverages AI to connect people with the real-world wisdom of Reddit communities. We’re hiring Senior and Staff Machine Learning Engineers to make Answers smarter, more relevant, and more helpful. Our SOTA AI systems helps surface the right conversations, but the heart of Answers is still people helping people ~ Redditors sharing what they know with each other!

• Recommendations, search, content understanding, or large-scale data and ML infrastructure
• SOTA large scale RecSys 
• Foundational retriever models
• RAG systems, retrieval methods, LLM evaluation, or production LLM features
• Agentic AI, such as tool calls, MCPs, multi-agent systems, or orchestration
• Self-hosted open-weight models such as Qwen or Llama; prompt engineering, fine-tuning, post-training, or prompt optimization
• Improving grounding, instruction following, and hallucination; evaluating retrieval and generation quality
• Scaling LLM systems, including latency, caching, and cost; safety measures for prompt injection and unsafe inputs
• Defining product success metrics, feedback loops, and evaluation approaches, including human review

• →Build and improve large-scale ML systems, including retrieval and ranking, embeddings, and LLM-powered features
• →Set technical direction and deliver measurable user and business impact
• →Work with partner teams to shape product and technical roadmaps
• →Evaluate new AI/ML approaches and support responsible LLM development
• →Mentor engineers and contribute to long-term ML planning

• 4–12 years of experience building, deploying, and operating ML systems in production
• Broad knowledge of ML fundamentals and experience applying them in production; expert-level modeling depth isn’t required
• Experience developing and productionizing models with TensorFlow, PyTorch, or Hugging Face Transformers
• Experience writing production-quality code, including testing, evaluation, and monitoring; Python experience required, Golang experience a plus
• Experience with ML systems such as data pipelines, feature engineering, model training and serving, and production monitoring
• Strong communication and collaboration skills, and a record of delivering measurable product impact

This job posting may span more than one career level.

In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit https://www.redditinc.com/careers/.

To provide greater transparency to candidates, we share base salary ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below.