my co-founder and I don't pair program per se but we both are familiar with each other's main domain and often switch (front end/back end) when the other is stu

my co-founder and I don't pair program per se but we both are familiar with each other's main domain and often switch (front end/back end) when the other is stuck or frustrated. this works pretty well, I've found, and has the added bonus that we both know the product back to front.