  We construct UV completions of bottom-up models with a pseudo Nambu-Goldstone
Boson (NGB) composite Higgs and partial compositeness, admitting a weakly
coupled description of the composite sector. This is identified as the low
energy description of an SO(N) supersymmetric gauge theory with matter fields
in the fundamental of the group. The Higgs is a NGB associated to an
SO(5)/SO(4) coset of a global symmetry group and is identified with certain
components of matter fields in a Seiberg dual description of the theory. The
Standard Model (SM) gauge fields are obtained by gauging a subgroup of the
global group. The mass mixing between elementary SM and composite fermion
fields advocated in partial compositeness arise from the flow in the IR of
certain trilinear Yukawa couplings defined in the UV theory. We explicitly
construct two models of this kind. Most qualitative properties of the bottom-up
constructions are derived. The masses of gauge and fermion resonances in the
composite sector are governed by different couplings and can naturally be
separated. Accommodating all SM fermion masses within the partial compositeness
paradigm remains the main open problem, since the SM gauge couplings develop
Landau poles at unacceptably low energies.
