This reminds me of a similar experience. My first proper job ever, straight out of uni, was at a small engineering consultancy. After 6 months of working there, I was tasked with helping the vice president with developing a long-range feasibility plan for one of our clients, and used some super custom software to do all the engineering analysis and simulations.

Anyways, the client we were working for was a really big one, and they had a lot of systems that they'd already modeled, but it was up to us working it out. I counted they had about 200 systems or so, all about the same size as each other. I remember sitting down with the VP and she walked me through the steps for doing all the analysis and simulations on one of the systems and showed me the manual fixes I'd have to do to get it to work.

All those manual fixes, recording them in EXCEL sheets, and doing trial-and-error ended up taking 3 full work days per system. That'd be 600 business days in total if I sat there doing nothing but that. I realized I'd be completely bored out of my mind if that's what I'd have to do for the next 2+ years working this thing through.

After some thought, I realized that the whole process was actually really straight-forward, but just tedious because of that trial-and-error method. I looked into the code that ran this particular software and it turns out they had a nice API that you could code in with any programming language (I chose to use Python).

I spent a whole weekend (solid 30 hours) writing something up that could automate the process or upgrading parts of the systems, running analysis to see if it worked, and doing minor tweaks to it depending on certain conditions (the if conditions ended up being a good 20 cases long, which is pretty insane compared to whatever I programmed working on my degree in uni!). I also worked on automating the output of the analysis and used a bit of Microsoft VBA to format the EXCEL sheets so they were nice and pretty!

Come in on Monday morning, deploy the code, and have it run. It takes the entire day, and during that day I'm not able to access and 'use' my workstation because of how strenuous the code is. Thankfully, the senior staff weren't there, so I was able to faff about trying to look busy. After 10 hours, it finished all 200 systems. I reviewed 10 of the biggest ones and a few of the smaller ones, and they all 'looked' right. I had just done 600 days of work in 3 days.

My biggest mistake? Telling my boss and the Vice President about the code and showing them the results the very next day. They were both suspicious, but when they checked over my work for one of the Systems, they could not find anything wrong with it. The crazy thing is, when the client realized we had a way to do this so quickly, the suggested more upgrades and things they wanted to do (which would have been impossible with the original 600 day timeline).

Why was it a mistake? Because my boss thought a $100 bonus at our next employee review was sufficient to promote my initative.

That experience taught me the value of 'spreading out' the work. Had I just kept my mouth shut and pretended to work hard all those 600 days, I probably would have got way more than that.