Senior Machine Learning Engineer - Search - London

Perplexity is seeking an experienced Senior Machine Learning Engineer to help build the next generation of advanced search technologies, with a focus on retrieval and ranking.

Responsibilities

• Relentlessly push search quality forward—through models, data, tools, or any other leverage available
• Architect and build core components of our search platform and model stack
• Train and evaluate retrieval, ranking and classification models, including LLMs
• Deploy models - from boosting to LLMs - in a scalable and performant way
• Build and optimize RAG pipelines for grounding and answer generation
• Collaborate with Data, AI, Infrastructure and Product teams to ensure fast and high quality delivery

Qualifications

• Deep understanding of search and retrieval systems, including quality evaluation principles and metrics
• Proven track record with large-scale search or recommender systems
• Hands-on experience with transformer-based models for dense retrieval, ranking, and classification in large-scale search systems
• Master’s degree or PhD in Engineering, Computer Science, Math, Physics, or a related field.
• 8 years of experience in software development and with data structures/algorithms in either (C, C++, Python, Java, Go or Rust).
• 5 years of experience with ML design and ML infrastructure (e.g., model deployment, model evaluation, data processing, debugging, fine tuning).
• 5 years of experience designing, training, and evaluating machine learning models.
• 3 years of experience in a technical leadership role leading project teams and setting technical direction.
• Self-driven, with a strong sense of ownership and execution

Our cash compensation range for this role is $160,000 - $250,000.