ML Breadth

Revision Topics

Fundamentals

  1. Math

  • Matrix Factorizations - Eigendecomposition, SVD, QR, Cholesky, PD/PSD

  • Matrix Calculus, Vector Calculus, Multivariate Chain Rule, Backprop derivation

  • Taylor’s Expansion, First and second order Approximation

  • Convex Optimization: GD, Newton’s Mehtod, Gauss-Newton’s Approximation

  • Optimizers: SGD, AdaGrad, RMSProp, Adam - Learning Rate, Schedule, Choice of parameters, Effect of Regularisation

  • Constrained Optimization: Lagrange Multipliers, KKT Conditions

  • Mercer Kernels, Reproducing Property

  1. Stat

  • Expectations, Higher Moments, Skew, Kurtoisis, Conditional, Marginal, Joint, Bayes Theorem

  • Variance Covariance Matrix, Scatter Matrix, Correlation Matrix, Eigendecomposition

  • Distributions and moments - Bernoulli, Binomial, Categorical, Multinomial, Normal, Poisson, Exponential, Logistic

  • Frequentis Estimation Theory - Point Estimation, Confidence Interval, Hypothesis Testing

  • Point Estimation, Bayes Estimator, Bias Variance Decomposition

  • Minmax Theory, Empirical Risk Minimization

  • Bayesian Estimaton Theory, Conjugate Priors - Normal, Beta-Binomial, Dirichlet-Multinomial

  • Sampling Techniques: CDF-Jacobian, Monte Carlo Estimators, Metropolis Hasting, Adaptive Metropolis Hasting, Ancestor Sampling

  1. Learning Theory

  • KL divergence, Entropy, MaxEnt, Cross-Entropy, NLL

  • Graphical Models - BN, MRF, CRF

  • Variational Inference, Belief Propagation, Deep Belief Net

  1. Regression and Classification

  • Bayes Estimator - Estimator for conditional mean (regression) or conditional mode (classification)

  • Basis Expansion, Gram matrix, Feature Maps

  • Linear Regression, Logistic Regression, Naive Bayes, SVM

  • Tree Based Methods: DT, Bagging, Boosting, XGBoost

  1. Clustering

  • Distance Based: K-Means, Density Based: DBSCAN

  • Hierarchical Clustering, Self-Organizing Maps

  • Metrics - Distance Based (Silhoutte coefficient), DB index, CH index

  1. Manifold Learning

  • t-SNE

  • Spectral Clustering

  1. Latent Variable Models

  • GMM, PCA, Kernel-PCA, ICA, CCA

  • NMF, LDA

  1. Outlier prediction

  • Isolation Forest

  • One-Class SVM

  1. Density Estimation

  • Linear/Quadratic Discriminator Analysis

  • Kernel Density Estimator

  1. Practical

  • Feature Engineering

  1. Reinforcement learning

  • SARSA

  • Explore-exploit, bandits (eps-greedy, UCB, Thompson sampling),

  • Q-learning, DQN

  1. Learning To Rank

  • Predicts a relative-order

  • Metrics: MAP, Precision@k, Recall@k, DCG@k/NDCG@k, MRR)

  • Common Approaches: Pairwise

Esoteric Topics

  • Ordinal Regression - predicts a class label/score (check this)

  • Causal reasoning and diagnostics, Causal networks

  • Learning latent representations

  • Bayesian linear regression

  • Gaussian Processes

Study Framework

  • Problem

    • Problem description and assumptions for simplicity.

  • Approach and Assumptions

    • Theoretical framework & motivation.

    • Mathematical derivation of training objective (loss) with boundary conditions.

    • What-if scenarios where training fails - mathematical issues (check stack-exchange).

  • Training and Validation

    • Design the training algorithm

    • Implementation and computational considerations including complexity.

    • Convergence checks.

    • What-if scenarios where training fails - computational issues (check stack-exchange).

  • Testing and Model Selection

    • Overfitting/underfitting checks and remedies.

    • Metrics to check - different choices and trade-offs.

    • Hyperparameter tuning and model selection.

  • Inference

    • Computational considerations.

    • Model degradation monitoring and remedies.

Sample Questions

Sample questions moved to the question bank in docs/source/gen/interviews/qb.rst.

Statistics

Question prompts moved to the question bank in docs/source/gen/interviews/qb.rst.

Classical ML

Question prompts moved to the question bank in docs/source/gen/interviews/qb.rst.

Applied ML

Question prompts moved to the question bank in docs/source/gen/interviews/qb.rst.

Mixture

Question prompts moved to the question bank in docs/source/gen/interviews/qb.rst.