Comment by pbalau

This was also posted internally and somebody else had a better way imho: after every weekly sync, he would take the bullet point list of things everybody in the team worked on/will work on and see if he can explain to an outsider what every item means. If yes, then check that out. Take all the remaining items, grouped by person and have 1:1 with said person to explain you the things you don't understand. Then you can set up a goal, like after 6 months I want to be able to strike out 70% of the items etc.