Having been in that situation and developed SW in house as well as hired third-party firms to do so, based on my experience I would go with in-house if 1) you h

Having been in that situation and developed SW in house as well as hired third-party firms to do so, based on my experience I would go with in-house if 1) you have very specific requirements that need to be well understood and implemented, and which may require close collaboration with the teams who are actually using the SW; 2) the SW in question is mission critical; 3) you want to be able to make changes/adjustments fairly quickly without the overhead of administrative/contractual dealings with a third party (i.e., whether it fits under existing SOW etc.).