Two-loop virtual amplitudes for $q\bar{q} \to t\bar{t}H$ production (the N$_f$-part)

In this article we briefly review the recent calculation of the part of two-loop virtual amplitudes for $q\bar{q} \to t\bar{t}H$ production proportional to the number of light and/or heavy quark flavours, the methods and tools employed (integral evaluation via sector decomposition with pySecDec, and IBP reduction with Rational Tracer), with an eye towards the full NNLO calculation.