Favourite aspect of the job? I love the fact that (nearly) every day I can look at something that didn't exist or didn't work when I started, and does now. Instant gratification!
Has serendipity played a role in your career? Certainly, in that it was just as much who I knew as what I knew that got me the first position at the hospital. Networking, even inadvertent networking, was hugely important for me initially, and the continued expansion of my role has been largely due to word of mouth as well. Also, in a larger sense, the need for the systems I've built is a reflection of the current fiscal climate (people wanting - or being forced - to justify funding) so that's another thing I had no control over.
Do I consider myself a systems thinker? A great deal of what I do is trying to find more efficient ways to get from A to B. It's certainly very useful to be able to take a step back and see whether B is actually the appropriate goal, and whether the current route has been working well or is the best. Just because the current system works doesn't mean it's the most efficient, or even that it works well.