TY - JOUR A1 - Besançon, Mathieu A1 - Garcia, Joaquim Dias A1 - Legat, Benoît A1 - Sharma, Akshay T1 - Flexible Differentiable Optimization via Model Transformations JF - INFORMS Journal on Computing N2 - We introduce DiffOpt.jl, a Julia library to differentiate through the solution of optimization problems with respect to arbitrary parameters present in the objective and/or constraints. The library builds upon MathOptInterface, thus leveraging the rich ecosystem of solvers and composing well with modeling languages like JuMP. DiffOpt offers both forward and reverse differentiation modes, enabling multiple use cases from hyperparameter optimization to backpropagation and sensitivity analysis, bridging constrained optimization with end-to-end differentiable programming. DiffOpt is built on two known rules for differentiating quadratic programming and conic programming standard forms. However, thanks to its ability to differentiate through model transformations, the user is not limited to these forms and can differentiate with respect to the parameters of any model that can be reformulated into these standard forms. This notably includes programs mixing affine conic constraints and convex quadratic constraints or objective function. Y1 - 2023 U6 - https://doi.org/10.1287/ijoc.2022.0283 ER -