I will discuss the telescoping deconstruction (TD) framework and its applications in many contexts, including boosted particle tagging, jet grooming and heavy ion jet modification studies. TD represents jet substructure information using a fixed-order subjet expansion with multiple angular resolutions. Specifically, using TD I will show the dominant feature of color-singlet jet isolation for boosted electroweak boson jets and its analytic understanding using soft-collinear effective theory. I will discuss a class of collinear-drop observables and their use in non-perturbative and jet modification studies. Also, I will show how QCD splitting function can be probed by TD subjet kinematics, and how TD variables can help reveal characteristic features of jet modifications in heavy ion collisions.