Title: Optimisation of quantum computations using the graphical ZX-calculus Myriam Backens Abstract: Quantum computational resources are currently very limited and will likely remain so for some time. This means it is vital to optimise a computation before running it on a quantum computer. In this talk, I will present strategies for optimising quantum circuits that make use of the ZX-calculus, a more flexible and fully rigorous graphical representation of quantum computations.