Corollary 1
Tag 00EM, permanent. Cite it as [Bourbaki, Tag 00EM].
Algebra, VIII, p. 221, § 12. Tensor Products of Semisimple Modules
Let and be semisimple K-algebras; suppose that is finite-dimensional over K. Suppose that the center of or is a separable algebra over K, which is, for example, the case when K is perfect. Then is semisimple.
This is the case of the corollary of VIII, p. 221.
Bourbaki sets the proof directly after the statement, and the corpus does not separate them, so what is above is the statement and its proof together.