I joined a dev team of six two month ago. People are nice, all is good. But more and more I observe an ad-hoc mindset. Stuff gets quick fixed, at the cost of future usability, there is little testing and two people happily admitted, that they like to carry the knowledge around in their head, rather than to write it down.

How to deal with this? I'd like to lead by example, but time is limited - I like architecting and actually implementing the stuff. But I'm afraid the ad-hoc mindset infects me and rather than striving for clearness and simplicity in design and code - which isn't simple to establish - I get pulled down the drain of an endless spiral of hacks on hacks - which no outsider can uncouple - just for schedule's and management's sake.