I used to keep a record of jobs done when I was initially doing type certs as most U.K.engineers did. Unfortunately I am bone idle about anything to do with paperwork so gave it up :-I find paperwork in this business a necessary evil and sometimes it can detract from the actual engineering!!!! In the U.K. I reckon word of mouth about an individual's capability is the most used and reliable method. Paperwork, unless strictly controlled can be a misleading source.
For instance I've known contractors with no aircraft experience falsify documents and subsequently end up working on aircraft.(one individual in particular who used to work on a car assembly line is now an a/c maintenance manager---oh dear)