You're probably confusing ARPACK with BLAS / LAPACK.
Pure julia ARPACK already exists, e.g. https://github.com/haampie/ArnoldiMethod.jl/.
A competive BLAS-gemm is implemented here https://github.com/YingboMa/MaBLAS.jl/blob/master/src/gemm.j... (single-threaded).
A LAPACK-like library could be https://github.com/JuliaLinearAlgebra/GenericLinearAlgebra.j...