Internship - Search Machine Learning Engineer

Perplexity is hiring an Internship - Search Machine Learning Engineer in London, United Kingdom. Level rates it ; you can apply on Perplexity.

Level's read on this job

Builds AI ●●●● is how Level rates this machine learning engineer role: the job is building AI systems.
Tools and skills the posting cites include PyTorch, TensorFlow and JAX.
Level classifies it as an internship.
Level lists 130 other open roles at Perplexity.

AI in this role

pytorchtensorflowjax

ragnlp

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

How we rate this

Internship - Search Machine Learning Engineer at Perplexity rates 100 out of 100 for how much of the daily work is AI. That makes it Builds AI (AI Level 4 of 4). The level is about AI in the job, not seniority.

Classification

Builds AI. The job is building AI systems.

●●●● Builds AI80 to 100
●●●○ Works on AI60 to 79
●●○○ Uses AI40 to 59
●○○○ Little AI0 to 39

Levels come from how often the tools, models and workflows of the role are named in the posting itself. Read the description and count the AI tools, models and workflows it names.

Key facts

Internship - Search Machine Learning Engineer is an open job at Perplexity.
Level rates this role AI Level 4 of 4: Builds AI.
The role is based in London.
The job was posted on April 8, 2026.
Seniority: intern.
Applications are handled by Perplexity. Apply on Perplexity

Prepare for this job

Built from this posting and from similar jobs on Level.

Skills and AI tools this role asks for

RAGNLPPyTorchTensorFlowJAX

Also common in machine learning engineer jobs at this level

Deep learning AWS Generative AI C++Kubernetes Spark

Pay

Typical machine learning engineer job: $199k

This posting doesn't list pay. Use the typical machine learning engineer figure when pay comes up. See machine learning engineer jobs

Questions you could be asked

How would you design a retrieval step so the model answers from real data instead of guessing?
What NLP problem have you worked on, and how did you measure whether it actually worked?
What are the limits of PyTorch that you've run into, and how did you work around them?
What's a project where you used TensorFlow hands-on?
Walk me through how you've used JAX in your day-to-day work.

Adapt your resume

List these exact terms on your resume: RAG, NLP, PyTorch, TensorFlow, and JAX. An applicant tracking system matches the wording, not the idea.
Attach one line of real, concrete experience to at least one of them. A tool named with nothing behind it rarely survives a human read.
Lead with what you built, trained or shipped. This role is judged on the AI system itself, not the tools around it.

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