Some recent developments in nonleptonic $B$ decays

I report on three recent topics from the field of two-body nonleptonic decays of $B_{(s)}$ mesons. The computation of two-loop NNLO corrections to the leading penguin amplitudes in QCD factorisation, puzzles that have emerged in colour-allowed tree-level decays to heavy-light final states, and a combination of QCD factorisation with $SU(3)$ flavour symmetry to estimate the size of weak-annihilation amplitudes.