#machine learning

9 machine learning interview questions, asked at Meta, OpenAI, Amazon and 5 more companies. Last asked Sep 2026.

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Vectorized nearest-neighbour classifier as a linear layerCodingImplement a 1-nearest-neighbour classifier in NumPy with no Python loops. Then rewrite it as the forward pass of a small network, a matrix product plus a bias followed by an…
Last asked Sep 2026
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Find noisy annotators and retrain a classifier without themCodingA classifier is trained on labels from several human annotators, and some of them label carelessly. Find which annotators are unreliable, drop their labels, retrain, and show…
Last asked Sep 2026
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Implement k-means clusteringCodingImplement k-means from scratch: initialize k centroids, assign every point to its nearest centroid, move each centroid to the mean of its points, and repeat until the assignments…
Last asked Sep 2026
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Linear regression with hand-written gradient descentCodingFit a one-feature linear regression by gradient descent on mean squared error, without an ML library. Then discuss choosing the learning rate, when to stop, and how to spot a…
Last asked Sep 2026
Cross-entropy loss with masking and label smoothing in NumPyCodingImplement cross-entropy loss over a batch of logits in NumPy, stable for large values. Add a mask so padded positions do not count, then add label smoothing. Be ready to explain…
Last asked Jul 2026
Train and improve a binary classifier with scikit-learnCodingGiven a small labelled dataset, train a binary classifier with scikit-learn, report a sensible evaluation metric, and then improve it through feature handling, model choice or…
Last asked Dec 2025
Timed ML screen: concept questions, then classic models from scratchCodingA timed online screen for ML-leaning engineers, about ten items in a little over an hour: 1. Multiple-choice ML concepts: compute recall from a confusion matrix, compare bagging…
Last asked Dec 2025
Write a text parser and fix the bugs in an ML projectCodingIn a one-hour round on an existing ML project: first write a parser that turns raw text data into the format the project needs, then find and fix three bugs elsewhere in a fairly…
Last asked Sep 2025
Scaled dot-product attention from scratchCodingWrite scaled dot-product attention by hand: from queries, keys and values, compute the scores, scale them by the square root of the key size, apply an optional mask, take a…
Last asked Sep 2025