Multi-team development is radically different to a two-person project, especially when it's in production with lots of money depending on it.

You can't rewrite much without the risk of breaking things, so you need a lot more testing. There's a lot of value in the code, so there's more to leverage to add functionality, but the other side is there's more to learn and analyze to efficiently leverage. And when there's lots more teams working on the code, there's more of it and it changes faster than you can expect to fully comprehend; you're continually analyzing and learning.

When I'm off on my own, spiking a new service or library, I can churn out 10k to 20k lines a month; it's very easy when it's greenfield, when there's no team coordination overhead, when you don't need to refactor other people's stuff when you redesign, you don't need to go through full code review cycle, the whole thing fits inside your skull etc. But that doesn't last forever, and it's not business as usual for feature development.

Fixing a gnarly bug might take several days of investigation and end up with a 1 line fix; and delivering that fix might make the difference in avoiding 6 or 7 figures worth of revenue churn. Does that mean it's 10000x less productive?

It sounds like you wrote 20-30 lines per day part-time over 10 years, which is within an order of magnitude of 10 lines per day for the average developer. Sounds about right to me?

> I didn't spend 15 years writing it. It's a part-time effort over 10 years.

It's not that far off. I'm taking your example as rather confirming the point rather than refuting it.

2 people is a pretty small project and by the looks of it it probably didn't involved nearly as much coordination as most large business apps. I also imagine you didn't have to do much coordination with project managers, qa, business analysts, architects, other devs, etc.

When I worked on a big project (several million lines of code) I routinely would code less than 10 lines per day.

> 10 lines per day is just rubbish.

For you. For the average developer, on the large scale, I think it is closer to the truth than you'd think.

It doesn't sound like this was done within the context of a corporation, which slows things down a lot. Also, it has 424 open issues right now--is it really bug fixed?

(Also, not a fan of back-jumping 'goto's or putting executables in git repos. And s/supressing/suppressing/g)

You seem like a fine programmer, but I don't think this invalidates MMM.

Recommend me an architecture concept or book. I’m trying to learn how to keep my “velocity” up over time

Edit: you made Sumatra?? I’ve been using that for a decade, thank you so much for creating it! I put it on all my family’s machines, it’s the fastest PDF reader I’ve found

Braid was 3+ years iirc (according to a gamasutra interview I read)