Steven G. Johnson

Steven Glenn Johnson (born 1973) is an American mathematician known for being a co-creator of the FFTW library for software-based fast Fourier transforms and for his work on photonic crystals. He is professor of Applied Mathematics and Physics at MIT where he leads a group on Nanostructures and Computation.
While working on his PhD at MIT, he developed the Fastest Fourier Transform in the West (FFTW) library with Matteo Frigo; they were awarded the 1999 J. H. Wilkinson Prize for Numerical Software for this work.
He is the author of the NLOpt library for nonlinear optimization. He is a frequent contributor to the Julia programming language, and has also contributed to Python, R, and Matlab. He was a keynote speaker for the 2019 JuliaCon conference.