1) The product is horizontally scalable to 3 orders of magnitude more traffic than the product will ever receive.
2) Bespoke assembler/hand crafted memory management/other do not touch code to shave 5ms off a 5 ms call on an API that isn't latency sensitive.
3) Ability to handle N customer tenants while only handling 1 customer 3 years later.
4) multi-region redundant deployment for 1 customer strictly based out of the US with no availability requirements.
5) 100% coverage for integration tests, unit tests, CI/CD, for a single tenant blog that is never updated and no one reads.
6) Custom internal framework with micro-service splits to support team of 100 engineers working on app when there are 2.
7) Automated continuously trained ML ranking model which performs .001% better than sorting by popularity or other trivial heuristic on a social media app with 10 users.
The common theme in many of these cases is that these are pretty good ideas if you have unlimited people, but have fairly low impact. In some cases these may be counter-productive to successful delivery at the company/product level. A piece of software built wrongly due to poor understanding of the product domain is often considered under-engineering.
It's completely wrong given the context 99% of companies are operating in. It's no wonder a Zuckerberg can come along and build a crazy successful company in his early 20s. He likely didn't know any "best practices". Common sense was enough.
In my org, we love to call this out with an (often private) "We need to do it because Google Does it!" -comment.
Some of it makes sense when the reasons were explained (e.g. "we figured this would make it easier for [business unit] to do [thing] which turned out not to be something [business unit] actually has interest in doing").
Other examples are purely of this sort (e.g. "we'll be glad we have this in place when we finally hit [x] users or enter [market]").
Design wise, I know it when I see it but other people may see different things.
I agree completely on pushing off features that are not core because it is better to learn in production than to daydream in meetings. I would say most phase-2 features never get implemented.
Complexity kills projects and the will to work on them. It can be caused by either over or under-engineering. With the first you end up with extraneous layers of abstraction and badly applied design patterns that make it hard to understand or reason about the code...in the second you end up with a big ball of mud that's impossible to understand or tease apart.
In both cases the code gets harder and harder to change to the point that no one really knows how it works or wants to risk touching it.
No tests? Nobody knows how it works? It doesn't perform well and doesn't fit the problem it's solving? That's very much not over engineered in my book.
> and the engineer who wrote most of the code has argued that we don't need tests, for various reasons
Sounds like you made the right choice to walk away. "My code doesn't need tests" smacks of match-over-the-shoulder type of chaos creation. This person has likely never had to maintain their own code or someone else's, nor has anyone ever had to maintain their code. 0/5 would not work with.
Tests are wonderful. Tests are proof your code works. They are something to be proud of. And they defend your code against the chaos monkey of future people refactoring and rearranging.
All it takes is a good enough sales and marketing team, or the right executive relationships, especially if the team being “supported” is small.
You can say the company or division is presently functioning, but the time constant on the product is different, and the coupling is too loose to say anything else with accuracy.
That's the point though. Getting caught up in engineering purity or even whether it's objectively _good_ is a waste. The product exists to drive business (financial) metrics. If it's doing that, it's working.
If the product is poorly crafted, and especially if it's also poorly tested, adding features can introduce bugs, and fixing bugs in one place can cause issues elsewhere. Development then slows to handle these occurrences, which can then impact product viability.
> Does the product generate the revenue for their paychecks, plus extra for the company?
You want to be comfortably generating/contributing more revenue than the expense of employing you.
I'm currently walking away from a code-base (and the company who let it be built) that was obviously built by someone who's mental model of how the code works was incorrect. At some very basic levels, it under-performs compared to literally every other example of this sort of code I've ever seen (and it's extremely common), which results in a subpar user-experience and an EC2 instance way bigger than necessary to run this sort of code. A lot of code running doesn't need to run in the first place, and due to the incorrect mental model, there's a substantial amount of code that doesn't run.
Nobody really understands how bad it is, though, because it's barely tested (and the engineer who wrote most of the code has argued that we don't need tests, for various reasons) and all of the engineers on the team who didn't build it initially, have told me that they're not familiar enough with how this sort of product should work to understand that it doesn't work like that (again, this is a super common kind of product).
There's a lot of other anti-patterns (I started keeping a list in my first week) but I think these are the most damning. This code is in production. Nobody at the org brought up these issues earlier in development (like saying "hey, nobody else's product does [annoying thing that doesn't need to happen], why does ours?"), which leads me to believe that the whole technical org is at fault.
It sucks and I can't wait to be done with this experience.