Machine Learning Engineer, Ranking & Retrieval

Location: United States Workplace: Remote At ClickUp, we're building the future of work: the first truly converged AI workspace unifying tasks, docs, chat, calendar, and enterprise search, all supercharged by context-driven AI. We are an AI-native company. Every team member is expected to leverage AI daily, and we evaluate AI fluency as part of our hiring process. Join us and help redefine what's possible. 🚀 Machine Learning Engineer, Ranking & Retrieval ClickUp is seeking an experienced Machine Learning Engineer to join our Search team. You'll own the ML systems that power search relevance for millions of users and ground our AI in the right context. Your Impact at ClickUp You'll own the full ML lifecycle for ranking and retrieval, from training through deployment and production serving. Our search indexes large-scale, user-generated content across a multi-tenant platform where permissions-aware retrieval is critical. You'll build the systems that decide what surfaces first. Core Responsibilities - Train, deploy, and serve ranking models in production, owning the full ML lifecycle - Build ranker features, training pipelines, and offline evaluation frameworks - Design and scale hybrid retrieval combining lexical and vector search (including HNSW with disk offloading) - Run embedding inference at billions-of-documents scale - Improve query understanding through intent modeling and query expansion - Build permissions-aware retrieval that respects multi-tenant boundaries - Create measurement frameworks to evaluate and improve search quality - Collaborate with Search Infrastructure, AI, and backend teams to integrate ranking improvements across the platform Technical Requirements - Bachelor's degree in Computer Science, Machine Learning, or related field - 5+ years of ML engineering experience focused on ranking, retrieval, or information retrieval - Proven full ML lifecycle ownership: training, deploying, and serving models in production - Hands-on ranker model training: feature engineering, pipelines, offline evaluation - Experience building hybrid (lexical + vector) retrieval systems - Experience running embedding inference at large scale - Strong query understanding fundamentals: intent modeling, query expansion Preferred Qualifications - Permission-aware retrieval and multi-tenancy experience - Indexing large-scale user-generated content (not small or static datasets) - Hands-on experience with OpenSearch or Elasticsearch - Sharding, index management, and real-time ingestion at scale - Background in NLP, semantic search, or agentic retrieval - Experience with TypeScript in backend systems   Join Our Mission At ClickUp, we're committed to building the future of productivity software. As our Search Engineer, you'll play a crucial role in shaping the core functionality of our platform and driving our AI initiatives forward. Join us in our mission to make the world more productive! #LI-REMOTE Equal Opportunity Employer ClickUp is an Equal Opportunity Employer, and qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, or national origin. Privacy Notice ClickUp collects and processes personal data in accordance with applicable data protection laws. You can find further details by viewing our Global Candidate Privacy Notice. https://clickup.com/careers-terms/candidate-privacy-notice If you are a Philippine Job Applicant, please also see our Philippine Data Privacy Notice https://t333.s.clickup-attachments-stg.com/t333/d9a53ce2-6d2c-48cd-84b1-ed4e525f9613/Philippine%20Data%20Privacy%20Notice_2024.pdf?view=open for further details. Visa Sponsorship Please note we are unable to sponsor or take over sponsorship of an employment visa for roles outside of engineering and product at this time. Sponsorship for engineering and product roles is not guaranteed, but is instead based on the business needs for that specific role at that time. Please reach out to the recruiter with any questions. Fraud Alert ClickUp Talent Acquisition will only initiate contact via an @clickup.com http://clickup.com email or through our official careers portal on clickup.com http://clickup.com. We will never request fees, payments, or sensitive personal information. Please disregard any offers received outside these channels and report them to support@clickup.com. AI Processing Notice ClickUp may use artificial intelligence and machine learning technologies to help review and screen candidates' employment applications against role-related criteria. These tools support, but do not replace, human decision‑making. If you have questions or need an accommodation in the recruitment process, please contact us at AskPeople@ClickUp.com.