do they in-between in house? or do they just give really detailed instructions to the in-betweeners?

Effectively all animation tasks except a small portion of the backgrounds in KyoAni productions is done in-house, and has been the case for over a decade. When it comes to the in-betweens, the only parts that aren't done in either Kyoto or Osaka are by St Blue staff, with whom they have that close of a relationship with (financially and creatively) anyways - some have eventually transferred to KyoAni itself.

KyoAni really stresses hiring good in-betweeners, this cut feels very representative of that

zaris said:
KyoAni really stresses hiring good in-betweeners, this cut feels very representative of that

Correction: it’s not just hiring “good” inbetweeners, that skill is developed in large part through the excellent training they give their in-house douga teams