[1] Mashey holds a Ph.D. in computer science from Pennsylvania State University,[2] where he developed the ASSIST assembler language teaching software.

[5] He continued similar work at Silicon Graphics (1992–2000), contributing to the design of the NUMAflex modular computer architecture using NUMAlink, ending as VP and chief scientist.

[5][6] Mashey was one of the founders of the Standard Performance Evaluation Corporation (SPEC) benchmarking group, was an ACM National Lecturer for four years, has been guest editor for IEEE Micro, and one of the long-time organizers of the Hot Chips conferences.

[5] He chaired technical conferences on operating systems and CPU chips, and gave public talks on software engineering, RISC design, performance benchmarking and supercomputing.

This story was featured in USA Today,[15] and he was interviewed in Science magazine, which stated that he was "spending his retirement years compiling voluminous critiques of what he calls the 'real conspiracy' to produce 'climate antiscience'.