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Hard · machine_learning · Quant Researcher interview question · lasso, coordinate_descent, regularization, feature_selection, machine_learning
Lasso regression is a key technique in quantitative finance for building sparse factor models, pruning hundreds of alpha signals into a parsimonious set. The coordinate descent algorithm provides an efficient, matrix-inversion-free method to solve the L1-penalized objective by iteratively updating each coefficient. This approach is fundamental to implementing scalable feature selection for return prediction and risk modeling. Task Implement the function lasso_coordinate_descent(X, y, alpha, max