What you are actually walking into, and what the rules allow.
Round 1 — the written qualifier
A three-hour proctored paper taken in person. The 2026 set was 24 pages and nine problems: short theory questions on unsupervised learning, regularisation, bias–variance and F1, then linear algebra and PCA, matrix decomposition, derivatives, vectorised NumPy, token embeddings, CNN feature-map reasoning, custom PyTorch modules, and a constrained tabular classification task scored on macro-F1 against hidden test data.
Round 2 — the invitational
Two in-person days for the top Round 1 scorers, hosted at major universities. Longer modelling problems replace the short-answer format, and the problems come with a published design rationale afterwards.
The national camp
A residential week of lectures and team selection tests. Performance across the TSTs determines who is named to Team USA — eight students for IOAI and four for IAIO in the 2026 cycle.
What you are allowed to use
PyTorch rather than TensorFlow, matching IOAI's requirement. Round 1 coding tasks are CPU-only unless a problem says otherwise, and individual problems impose their own import restrictions — the 2026 Problem 9 forbade deep networks entirely.