She is currently the Steven and Renee Finn Career Development Associate Professor of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology.

[2] She is notable for her breakthrough results in fast matrix multiplication,[3] for her work on dynamic algorithms,[4] and for helping to develop the field of fine-grained complexity.

[1] Her dissertation, Efficient Algorithms for Path Problems in Weighted Graphs, was supervised by Guy Blelloch.

[9][10] Williams was an NSF Computing Innovation Fellow for 2009–2011,[1] and won a Sloan Research Fellowship in 2017.

[2] She was an invited speaker at the 2018 International Congress of Mathematicians, speaking in the section on Mathematical Aspects of Computer Science.

[12] She is married to Ryan Williams, also a computer science professor at MIT; they have worked together in the field of fine-grained complexity.