  Spectral Mackey functors are homotopy-coherent versions of ordinary Mackey
functors as defined by Dress. We show that they can be described as excisive
functors on a suitable infinity-category, and we use this to show that
universal examples of these objects are given by algebraic K-theory.
  More importantly, we introduce the unfurling of certain families of
Waldhausen infinity-categories bound together with suitable adjoint pairs of
functors; this construction completely solves the homotopy coherence problem
that arises when one wishes to study the algebraic K-theory of such objects as
spectral Mackey functors.
  Finally, we employ this technology to lay the foundations of equivariant
stable homotopy theory for profinite groups and to study fully functorial
versions of A-theory, upside-down A-theory, and the algebraic K-theory of
derived stacks.
