[np_tedious]

That article is mostly about speed. The following seems like the one thing that might be relevant:

> Naively, you could take the random integer and compute the remainder of the division by the size of the interval. It works because the remainder of the division by D is always smaller than D. Yet it introduces a statistical bias

That's all it says. Is the point here just that 2^31 % 17 is not zero, so 1,2,3 are potentially happening slightly more than 15,16? If so, this is not terribly important

[lern_too_spel]

> If so, this is not terribly important

It is not uniformly random, which is the whole point.

> That article is mostly about speed

The article is about how to actually achieve uniform random at high speed. Just doing mod is faster but does not satisfy the uniform random requirement.

[np_tedious]

If your number of AB testing combos cohorts is fewer then 100 then yeah this passes for being uniform