Yesterday my colleague Niels and I went to the DDDBelgium meetup with a workshop on software design heuristics by Mathias Verraes. Find out here what we learned from it.
Workshop setup.
The workshop was in real DDD-style without digital tools and we used pen and paper, so there was no distraction. We started by dividing ourselves into groups of 2. Mathias asked us a question to first discuss from gut feeling and then in more detail how a system can send a certain message to another system.
The exact question was as follows:
There is a system (A) that calculates a prize up to 4 decimal places, and a system (B) that wants to receive that prize. How much information does the price contain that you send to system B, 4 or 2 digits. Several people in the audience had chosen 2 digits on gut instinct, and another part had chosen 4 digits.
After we had made our gut feeling known, we had to further discuss with our duos why we had made that choice. After that we distilled it into more generic patterns that can also be applied to other problems.