April is a compiler from a subset of the APL language to Common Lisp. In pursuit of a more performant and elegant implementation of APL, April has been reimplemented with lazy evaluation starting in 2022. This means that the compiler produces code generating a tree of objects representing deferred computations and transformations of arrays. The object tree’s methods are called to effect the generation of an output array, and at this time a second phase of compilation may be performed to generate optimized array-transforming kernels. This lazy evaluation model with runtime optimization is capable of yielding high performance from functions that can be elegantly specified thanks to the object-oriented programming faculties of Common Lisp.