Ask HN: What was your most humbling learning moment?

I've been working for the same company 10 years. When we built project A, I was surrounded by people who had built the same product for the past 20 years together. As a younger dev, I deferred to them as they were much older and had done this before. You would probably admire them. They pumped out code and delivered immense value. We had no over-engineering because there was no upfront design discussions. When we needed to use some service, we just wrote that directly in our normal framework code instead of using some over engineered abstraction. That's usually highly praised here on HN.

Years later, that project became an extreme maintenance burden. There is no separation of business code from framework code, so the first major framework migration took... years. When they completed the framework migration it was already 2 versions out of date. Subsequent upgrades were faster and given more priority, but still took multiple months. Onboarding new clients took whole teams. The code is fragile, lacks test, etc. The app is classic "spaghetti code". But they sure got to production quick!

Around 2.5 years ago, I was tasked with building project B. There was no development team. I worked with two domain experts, but ultimately the development of the product was in my hands. This is a product that will live on for at least another 10 years and will likely overtake our core product in revenue. There is no one to blame, but myself, if in 5-10 years this app becomes another unmaintainable mess. If you're in this position, what do you do? For me, all I could do is draw on my experience to try to avoid the mistakes I've seen made in the past. We made a lot of mistakes in project A, but I knew a big one was tying our business code, the core of our business, to the particular flavor of web framework that happened to be popular at the time the project started. How do you avoid that? Well, "Hexagonal architecture" sounds like a big scary buzzword, but it's a damn simple pattern that solves that elegantly. When we started, I basically received an indirect mandate that we use the same framework as project A. After we had written ~25k LOC, I had enough and we dropped that legacy framework and migrated to something much better. And we didn't have to change a single line of our business code. Our new framework allows us to iterate much faster than legacy framework. 2.5 years in and our code looks as clean as that initial POC I built. Hexagonal was a small bit of the initial architecture I did. I only point it out here as a counter example. But all the little things I've done which are considered "architecture" have paid off years down the road.

Maybe in the olden days. Not so sure the American dream is alive anymore.

I also learned about the buyer address for billing and delivery address feature for shipping things now known as drop shipping or re-selling.

I needed a computer so I sold quite a few hard drives and CPUs using eBay and supplies through another companies website. Once I received the money, I then purchased the item with my debit card I was given for “learning a checking/savings account”. I made enough for a computer and stopped. The humbling moment was a few years later when I realized I should have made that into a business. All of it was pre-internet taxation days too.