I was hired as an Oracle programmer in an IT department with two other people, including my boss. We were supporting a 6-office network of about 100 insurance agents and 60 support staff. A few months after I joined, my new boss left the company, and I took over the department. This was a very dangerous situation for the company, as I soon discovered. None of the systems had been documented and they were old, unreliable, and built on a UNIX platform that was by then obsolete. From the first day, we started getting a stream of urgent calls from salespeople who were unable to access the system, or couldn't make (or receive calls). Normally my old manager would have just fixed these problems himself, but with him gone and no documentation, we were stuck.

The first thing I did was to bring him back as a consultant, shadowing him as he solved the daily problems.  In this way, we began to build documentation for all of the functions our department was responsible for. As I became educated about how things worked, I also created a list of issues requiring more systematic attention. I was lucky to find a senior ally who realized the danger we were in. We reviewed the list I created, and together prioritized the issues and came up with recommendations for resolving them, which we presented to the owner. We convinced him that a new server platform and network were required. Over the next 6 months, we replaced the hodgepodge of systems we had been running, and deployed a new Windows server infrastructure and email system. We got rid of all the virus-infected stand-alone PCs our agents were using, and centralized our quoting system. 

The timing was perfect, since shortly afterwards the auto insurance industry experienced a boom, and over the next year our company grew from the original 6 offices to 24 offices, and quadrupled our sales and expanding to over 650 people. This wouldn't have been possible had we been on the old platform.