Hey! I'm David, the editor of the post you linked to. If there are any other topics you're interested in learning about, please let me know! We wrote another one on Salesforce (https://retool.com/blog/salesforce-for-engineers/) that was well received on HN too (https://news.ycombinator.com/item?id=20277115). We were thinking about writing about Marketo / marketing automation solutions next. (I'm david AT retool.com)

(As an aside — when we started Retool, we ourselves didn't expect the "custom internal tools" to be such a big market. As it turns out, we now have customers that spend $400M+ / year on building custom, homegrown, internal tools! While we [or any single vendor] certainly can't capture all of it, our goal is to capture some percent of it.)