Search Machine Learning Engineer Intern (AI)

Location: In-person in the Belgrade office, Serbia

Company

Perplexity develops advanced search technologies that help users search for and discover information.

What you will do

• Run experiments to improve search quality through better models, data usage, and evaluation tools.
• Design and implement retrieval, ranking, and classification components for the search platform and model stack.
• Train and evaluate models, including LLM-based approaches, for retrieval, ranking, and classification tasks.
• Support scalable deployment and monitoring of search and ranking models.
• Build and iterate on RAG pipelines for grounding and answer generation.
• Collaborate with Data, AI, Infrastructure, and Product teams to deliver production machine learning improvements.

Requirements

• Strong foundation in machine learning and statistics, with coursework or projects related to information retrieval, ranking, or recommender systems.
• Experience with Python and common machine learning frameworks such as PyTorch, TensorFlow, or JAX.
• Currently enrolled at a Serbian university in a Bachelor’s, Master’s, or PhD program, or self-taught with strong software engineering and technology skills.
• Ability to work comfortably in English in a collaborative professional environment.
• A completed personal project demonstrating initiative, ownership, persistence, and follow-through.
• Willingness to work in person at the Belgrade office.

Nice to have

• Experience evaluating model quality with offline metrics or A/B testing.
• Previous internship, research, or project experience in search, recommendation, or NLP.
• Experience with Rust.

Culture & Benefits

• Internship duration of 12–24 weeks.
• Full-time or part-time internship options.
• Mentorship and guidance from experienced engineers.
• Fast-paced, high-performance environment with direct feedback and high standards.
• Opportunities to learn production machine learning practices and take ownership of projects.