In the earlier days of my career, I was tasked with automating a large daily accounting task. Essentially, a team of accountants was copying and pasting values

In the earlier days of my career, I was tasked with automating a large daily accounting task. Essentially, a team of accountants was copying and pasting values outputted by the company ERP system into a spreadsheet. The ERP used an in-house database, and without intense reverse engineering it was only accessible via the internal programming language. Whilst the language did allow for File IO there was no real way to access the ERP without opening the GUI, so I wrote a dreadful little VBA script which invoked a logon for a dedicated user as a background session on a company server. When this user logged on, another little batch file opened the ERP GUI, opening the GUI triggered an action in the internal ERP language which checked to see if the username matched the special user. If so, the ERP began a vast series of complex calculations, spitting out the results to a series of files which were then read back by the VBA and populated the spreadsheet. The batch file on the background session would automatically log the session off after a pre-set time. Whilst this was all going on, the user in the spreadsheet was presented with a progress bar. If memory serves, I even had some primitive locking mechanism to prevent multiple people running this process at the same time. I think it ranks as the most hilarious (from a technical perspective) piece of work I've ever done. To my surprise, the solution was quite robust, and was being used on a daily basis by the CFO and other accountants. Even more surprising is that it carried on working for years, even long after I'd departed the company. Thinking back to that still makes me smile :)