Internship - Search Machine Learning Engineer at Perplexity (London, United Kingdom)
Perplexity· London, United Kingdom·
Role details
Perplexity at a glance
AI-powered answer engine that returns real-time, cited answers, now expanding into an agentic browser and on-device agents.
Perplexity runs an AI answer engine that searches the live web and returns direct, cited answers instead of a page of links. It has extended that core into an AI browser (Comet), an on-device agent (Computer), a developer API, and vertical tools like patent search.
$1.7B raised · latest: Series E extension · $200M · 2025 (reported $20B valuation) · backed by Accel, IVP, NEA, SoftBank Vision Fund 2
Summary
The Search Machine Learning Engineer Intern will collaborate with senior engineers to build advanced search technologies focusing on retrieval and ranking. Responsibilities include designing search platform components, training evaluation models, and improving RAG pipelines while contributing to feature shipment.
Job description
Perplexity is looking for a Search Machine Learning Engineer Intern to help build the next generation of advanced search technologies, with a focus on retrieval and ranking. You will work closely with experienced engineers to improve search quality, experiment with new models, and ship features that directly impact how users search and discover information.
Internship program: 12 - 24 weeks, full-time, in-person in the London office.
Responsibilities:
- Contribute to experiments that improve search quality through better models, data usage, and evaluation tools, under the guidance of senior engineers.
- Design and implement components of the search platform and model stack, including retrieval, ranking, and classification models.
- Train evaluating models (including LLM-based approaches) for retrieval, ranking, and classification tasks.
- Support deployment and monitoring of search and ranking models in a scalable and performant way.
- Help build and iterate on RAG pipelines for grounding and answer generation.
- Collaborate with Data, AI, Infrastructure and Product teams to deliver improvements quickly and learn best practices in production ML.
Qualifications:
- Strong foundation in machine learning and statistics, with coursework or projects related to information retrieval, ranking, or recommender systems.
- Experience with Python and common ML frameworks (e.g. PyTorch, TensorFlow, JAX) through academic, open source, or personal projects.
- Familiarity with evaluating model quality using offline metrics and/or A/B testing is a plus, but not required.
- Previous experience (internships, research, or significant projects) working on search, recommendation, or NLP is a plus, but not required.
- Self-driven and curious, with a strong sense of ownership, willingness to learn, and comfort working in a fast-paced environment
- Experience with Rust will be a plus
Why work at Perplexity
- Culture & Environment: “Thoughtful support” culture with emphasis on craftsmanship, ownership, entrepreneurship, scholarship, and partnership. Hybrid schedule (4 days in-office) based on location.
- Perks: Daily catered meals (breakfast, lunch, dinner in office), office snacks, ride home program, commuter benefits, home office reimbursement, fitness classes, gym memberships.
- Compensation & Benefits: Competitive salary and equity packages; retirement plans with company match; flexible PTO; holiday shutdown between Christmas and New Year; 12 weeks paid bonding leave; comprehensive health, dental, and vision insurance.
- Relocation & Visa Support: Relocation assistance and visa/green card sponsorship for eligible roles. Partners with immigration firm to support the process.
- Engineering Excellence: “Technical assessment for relevant roles”; values hands-on contribution, broad skill sets, and merit-based evaluation. Frequent Tech Talks and exposure to greenfield AI research problems.