Machine Learning & AI Topics
Production machine learning systems, model development, deployment, and operationalization. Covers ML architecture, model training and serving infrastructure, ML platform design, responsible AI practices, and integration of ML capabilities into products. Excludes research-focused ML innovations and academic contributions (see Research & Academic Leadership for publication and research contributions). Emphasizes applied ML engineering at scale and operational considerations for ML systems in production.
Model Evaluation and Validation
Comprehensive coverage of how to measure, validate, debug, and monitor machine learning model performance across problem types and throughout the development lifecycle. Candidates should be able to select and justify appropriate evaluation metrics for classification, regression, object detection, and natural language tasks, including accuracy, precision, recall, F one score, receiver operating characteristic area under the curve, mean squared error, mean absolute error, root mean squared error, R squared, intersection over union, and mean average precision, and to describe language task metrics such as token overlap and perplexity. They should be able to interpret confusion matrices and calibration, perform threshold selection and cost sensitive decision analysis, and explain the business implications of false positives and false negatives. Validation and testing strategies include train test split, holdout test sets, k fold cross validation, stratified sampling, and temporal splits for time series, as well as baseline comparisons, champion challenger evaluation, offline versus online evaluation, and online randomized experiments. Candidates should demonstrate techniques to detect and mitigate overfitting and underfitting including learning curves, validation curves, regularization, early stopping, data augmentation, and class imbalance handling, and should be able to debug failing models by investigating data quality, label noise, feature engineering, model training dynamics, and evaluation leakage. The topic also covers model interpretability and limitations, robustness and adversarial considerations, fairness and bias assessment, continuous validation and monitoring in production for concept drift and data drift, practical testing approaches including unit tests for preprocessing and integration tests for pipelines, monitoring and alerting, and producing clear metric reporting tied to business objectives.
Classification and Regression Fundamentals
Covers the core concepts and distinctions between classification and regression in supervised learning. Classification predicts discrete categories, either binary or multi class, while regression predicts continuous numerical values. Candidates should understand how to format and encode target variables for each task, common algorithms for each family, and the theoretical foundations of representative models such as linear regression and logistic regression. For regression, know least squares estimation, coefficients interpretation, residual analysis, assumptions of the linear model, R squared, and common loss and error measures including mean squared error, root mean squared error, and mean absolute error. For classification, know logistic regression with its sigmoid transformation and probability interpretation, decision trees, k nearest neighbors, and other basic classifiers; understand loss functions such as cross entropy and evaluation metrics including accuracy, precision, recall, F one score, and area under the receiver operating characteristic curve. Also be prepared to discuss model selection, regularization techniques such as L one and L two regularization, handling class imbalance, calibration and probability outputs, feature preprocessing and encoding for targets and inputs, and trade offs when choosing approaches based on problem constraints and data characteristics.
Model Selection and Hyperparameter Tuning
Covers the end to end process of choosing, training, evaluating, and optimizing machine learning models. Topics include selecting appropriate algorithm families for the task such as classification versus regression and linear versus non linear models, establishing training pipelines, and preparing data splits for training validation and testing. Explain model evaluation strategies including cross validation, stratification, and nested cross validation for unbiased hyperparameter selection, and use appropriate performance metrics. Describe hyperparameter types and their effects such as learning rate, batch size, regularization strength, tree depth, and kernel parameters. Compare and apply tuning methods including grid search, random search, Bayesian optimization, successive halving and bandit based approaches, and evolutionary or gradient based techniques. Discuss practical trade offs such as computational cost, search space design, overfitting versus underfitting, reproducibility, early stopping, and when to prefer simple heuristics or automated search. Include integration with model pipelines, logging and experiment tracking, and how to document and justify model selection and tuned hyperparameters.
Machine Learning and Forecasting Algorithms
An in-depth coverage of machine learning methods used for forecasting and time-series prediction, including traditional time-series models (ARIMA, SARIMA, Holt-Winters), probabilistic forecasting techniques, and modern ML approaches (Prophet, LSTM/GRU, Transformer-based forecasters). Topics include feature engineering for seasonality and trend, handling non-stationarity and exogenous variables, model evaluation for time-series (rolling-origin cross-validation, backtesting, MAE/MAPE/RMSE), uncertainty quantification, and practical deployment considerations such as retraining, monitoring, and drift detection. Applies to forecasting problems in sales, demand planning, energy, finance, and other domains.
Data Preprocessing and Handling for AI
Covers the end to end preparation of raw data for analysis and modeling in machine learning and artificial intelligence. Topics include data collection and ingestion, data quality assessment, detecting and handling missing values with deletion or various imputation strategies, identifying and treating outliers, removing duplicates, and standardizing formats such as dates and categorical labels. Includes data type conversions, categorical variable encoding, feature scaling and normalization, standardization to zero mean and unit variance, and guidance on when each is appropriate given model choice. Covers feature engineering and selection, addressing class imbalance with sampling and weighting methods, and domain specific preprocessing such as data augmentation for computer vision and text preprocessing for natural language processing. Emphasizes correct order of operations, reproducible pipelines, splitting data into training validation and test sets, cross validation practices, and documenting preprocessing decisions and their impact on model performance. Also explains which models are sensitive to feature scale, common pitfalls, and evaluation strategies to ensure preprocessing does not leak information.
AI and Machine Learning Background
A synopsis of applied artificial intelligence and machine learning experience including models, frameworks, and pipelines used, datasets and scale, production deployment experience, evaluation metrics, and measurable business outcomes. Candidates should describe specific projects, roles played, research versus production distinctions, and technical choices and trade offs.
Feature Engineering and Selection
Covers the end to end process of transforming raw data into predictive and stable model inputs and choosing the most useful subset of those inputs. Topics include generating features from domain signals and timestamps, numerical transformations such as scaling binning and logarithmic transforms, categorical encodings including one hot and target encoding, creation of interaction and polynomial features, construction of dense feature vectors for model consumption, handling missing values and outliers, and strategies for class imbalance. Also includes feature selection and dimensionality reduction methods such as filter techniques statistical tests wrapper methods embedded model based selection mutual information analysis and tree based importance measures. Emphasis is placed on avoiding data leakage validating feature stability over time interpreting feature contributions and documenting rationale for feature creation or removal. For senior roles include designing feature engineering best practices mentoring others and considering feature impact on model interpretability and business metrics.
Model Monitoring and Observability
Covers the design, implementation, operation, and continuous improvement of monitoring, observability, logging, alerting, and debugging for machine learning models and their data pipelines in production. Candidates should be able to design instrumentation and telemetry that captures predictions, input features, request context, timestamps, and ground truth when available; define and track online and offline metrics including model quality metrics, calibration and fairness metrics, prediction latency, throughput, error rates, and business key performance indicators; and implement logging strategies for debugging, auditing, and backtesting while addressing privacy and data retention tradeoffs. The topic includes detection and diagnosis of distribution shifts and concept drift such as data drift, label drift, and feature drift using statistical tests and population comparison measures (for example Kolmogorov Smirnov test, population stability index, and Kullback Leibler divergence), windowed and embedding based comparisons, change point detection, and anomaly detection approaches. It covers setting thresholds and service level objectives, designing alerting rules and escalation policies, creating runbooks and incident response processes, and avoiding alert fatigue. Candidates should understand retraining strategies and triggers including scheduled retraining, automated retraining based on monitored signals, human in the loop review, canary and phased rollouts, shadow deployments, A versus B experiments, fallback logic, rollback procedures, and safe deployment patterns. Also included are model artifact and data versioning, data and feature lineage, reproducibility and metadata capture for auditability, continuous validation versus scheduled validation tradeoffs, pipeline automation and orchestration for retraining and deployment, and techniques for root cause analysis and production debugging such as sample replay, feature distribution analysis, correlation with upstream pipeline metrics, and failed prediction forensics. Senior expectations include designing scalable telemetry pipelines, sampling and aggregation strategies to control cost while preserving signal fidelity, governance and compliance considerations, cross functional incident management and postmortem practices, and trade offs between detection sensitivity and operational burden.