We have increased the quantum volume to 64 on one of our 27-qubit quantum Processors.  This was possible through improving the compiler, calibrating faster two-bit gates, using dynamical decoupling, and an excited state promoted readout. Here is the paper https://arxiv.org/abs/2008.08571 

All this shows the need for lower-in-the-stack access to develop better quantum circuits.

I personally always love seeing dynamical decoupling making a difference. This was a very simple form so we can only get much more improvement. For those wondering what it is check out the early work by Lorenza Viola https://en.wikipedia.org/wiki/Dynamical_decoupling and the work of @MJBiercuk and @qctrlHQ

Also the ESP readout is cool. Using the extra levels of the transmon to boost measurement fidelity in a scalable way. It originated from this paper https://arxiv.org/abs/1005.5615