[5][2] She went to obtain her Ph.D. in computer science from Columbia University in 1992, studying under professor Calton Pu.
In October 1992, Massalin joined MicroUnity as a research scientist, where she became responsible for signal-processing modules and software architecture.
Massalin developed Synthesis, an operating system kernel that allocated resources, ran security and low-level hardware interfaces, and created executable code to improve performance.
[2] Synthesis optimized critical operating system code using run-time information, which was a new insight previously thought impractical.
"[2] She was well known for offering piggy back rides to people she met, which included notable computer scientists such as Dennis Ritchie, Ken Thompson, and artificial intelligence pioneer Marvin Minsky.