Mistakes engineers make in large established codebases

Post by cratermoon » Wed, Jan 08, 2025, 3:44 AM UTC

harrall wrote: post #77

cratermoon wrote: post #36

Earlier quoted context omitted.

I worked at a company that had a Rails monolith that underwent similar scenario. A new director of engineering brought in a half dozen or of his friends from his previous employer to write Scala. They formed up a clique and decide Things Were Going to Change. Some 18 months and 3 projects later, nothing they worked on was in production. Meanwhile the developer that was quietly doing ongoing maintenance on the monolit…

Also an issue is that the director attempted a full rewrite as a separate project. You can do successful rewrites but your rewrite has to be usable in production within like a month. If you don’t know how to achieve that, don’t even try. The quiet developer was able to get their own rewrite done because they understood that. Looks like the director of engineering showed some classic inexperience. You can tell when so…

Post by Tknl » Wed, Jan 08, 2025, 3:59 AM UTC

mjr00 wrote: post #107

photonthug wrote: post #97

Earlier quoted context omitted.

Even if you’re generally suspicious of so called best practice/ design patterns / Martin Fowlerisms.. this is a time for the strangler approach. (Parent and siblings are already talking about the same idea without naming it.) Rewrites from scratch never work with sufficiently large systems, and anyone that’s been involved with these things should be savvy enough to recognize this. The only question is around the exac…

A similar, more concrete approach is parallel implementations, as written about by John Carmack[0]. I suppose the main difference is that parallel implementation has you very explicitly and intentionally leave the "old stuff" around until you're ready to flip the switch. I've used this approach in large-scale refactorings very successfully. One of the benefits is that you get to compare the new vs old implementation…

Post by sverhagen » Wed, Jan 08, 2025, 4:10 AM UTC

peterldowns wrote: post #148

sfink wrote: post #138

Earlier quoted context omitted.

Hopefully, you have a monorepo or something with similar effects, and a lack of fiefdoms. In that case, if the current way is undocumented and/or inconsistent, you make it better before or while adding in your new approach. If there are 4 ways to do the same thing and you really want to do it a different way, then replace one of those ways with your new one in the process of adding it. For extra credit, get to the po…

I don't disagree with what you've written at all, but let me just say: > Hopefully, you have a monorepo or something with similar effects, and a lack of fiefdoms ah to be so lucky...

Post by usefulcat » Wed, Jan 08, 2025, 4:12 AM UTC

cratermoon wrote: post #149

mjr00 wrote: post #59

Earlier quoted context omitted.

> Meanwhile the developer that was quietly doing ongoing maintenance on the monolith had gradually broken out some key performance-critical elements into Scala and migrated away from the Ruby code for those features. Yep and that's what I've seen be successful: someone who really knows the existing code inside and out, warts and all, needs to be a key leader for the part being broken out into a separate system. The h…

> needs to be a key leader for the part being broken out into a separate system Indeed, the developer was one of the best programmers I've known and absolutely the key person on the system. The New Guys Clique were the sort of developers, you might know some, who come in, look at the existing systems, decide it's all wrong and terrible, and set out to Do It Right.

Post by accoil » Wed, Jan 08, 2025, 4:22 AM UTC

bryanrasmussen wrote: post #147

liontwist wrote: post #126

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This is totally fine. If you're given shit data this seems like a reasonable way to try to parse it (I would personally bound the loop). Typescript is not going to make it better. The problem is whoever is producing the data.

I think the complaint here is they have a string, which even has the word string in the variable name, and they turn it into an object at the end. Hence references to Typescript. I suppose what is wanted is something like let parsedJSON = {} try { parsedJSON = JSON.parse(susJsonString) } catch { //maybe register problem with parsing. }

    JSON.parse(JSON.parse("\"{foo: 1}\""))