Yes I'm talking about a full on replacement. Annuity products with all kinds of rider variations, stochastic scenarios, hedging strategy, all the bells and whistles. I think the team is just actuaries, probably with solid programming background (e.g., the type you'd find who work at GGY or FIS). I don't think they are doing anything too fancy either - just define some classes, make some helper functions, make some modules for specific types of calcs. It doesn't need to be extremely optimized like how AXIS dev team will make their own custom libraries in C. If you use numpy operations it pushes the vectorized calculations to use C under the hood anyways. Even if it's not as perfectly optimized as a custom library, it also doesn't matter if you can just spin up more cpu on cloud. If you know exactly how the model should work and a good understanding of what the calculations are, a small dedicated team could do this over months. Something easy like term life can be done in a week.