I watched a lot of that and used Clojure fulltime for five years. Wonder what he's up to these days.
Edit: Oh, there are streaming tickets for $20.
Turns out if you really focus on composability above other concerns you get Haskell.
Did he? I seem to remember a quip in one of the presentations about German not being comprehensible to him being his own problem, because he never learned German.
The Clojure tools.build process has this exact problem. It's too low-level, so everyone got to write their own build scripts on top of that to do the same thing as everyone else. Now there's a situation of a 1000s of bespoke build scripts and 3-4 different front-ends, all effectively doing the same thing.
"In my line of work, sister, sometimes a second chance is a chance to mistake the same mistake twice" - State and Main
How did that work out for you? Usually following a hype cycle, there is a negative hype cycle i.e. Mongo is webscale, then Mongo is a buggy mess.
Clojure seemed to just fade away. Did it turn out well or are there interesting pitfalls that make it not as great as advertised?
The best things about Clojure are things you don't really appreciate until you've already done the work to learn them.
For example, I never would have known how amazing it was to evaluate code inside the editor until I did the work of learning Emacs + evil-mode + nrepl/cider + whatever so that I could spin up my http server in-process and then modify code without restarting everything. Even today I'm doing `nodemon index.ts` like a goofball.
I stopped using Clojure simply when I met someone who wanted to build some big projects with me and, despite appreciating that Clojure was probably amazing, they simply couldn't be bothered to learn it. Fair enough. It was when Javascript was just getting `yield` coroutines (before async/await) which finally made Javascript bearable for me enough to switch to it for server work.
Clojure just has increasingly compelling languages and ecosystems to compete with, yet it has a huge ramp up, being a lisp, that make it hard for people to choose it.
Just consider how, to even write Clojure comfortably, you really need something like Paredit. Else, what exactly are you going to do if you want to nest or unnest a (form) deeper in the ast structure? Manually rebalance parens? Cut and paste it? Only Paredit lets you easily move a (form) around the ast. And it's amazing but yet another tool you have to learn just to truly evaluate Clojure.
https://shaunlebron.github.io/parinfer/
The size of the community is not as important as the value of what is available. It's just not widely known, or maybe there's still much potential yet unrealized.
This is an oldie but a goodie on how interactive an experience you can have when using Clojure on the front end and backend of a web app:
This project is the most recent and most promising iteration of someone making a very visual interactive tool for introspecting on data structures in the REPL environment
That said, I've been (and currently am) a Clojure engineer for the past 5 years and loving it. Quite a lot of jobs out there, more and more each time I look, healthy ecosystem and friendly community. It doesn't hurt that it's the most paid programming language as well.
> How did that work out for you?
For the personal projects, it's been incredibly useful. The language fits the way I think, and being built on the JVM, it has both a performant runtime and lots of access to a wide ecosystem of libraries.
The Clojure-specific ecosystem library has been accused of being stagnant. I tend to take a more charitable view. The libraries I've used have tended to be smaller in scope and more well defined in terms of feature set. This makes it easier for them to converge on a feature-complete state, and many of them have done just that. If you don't mind assembling multiple smaller libraries into the useful whole you need, this can provide a stable platform on which to build and develop expertise and higher level libraries.
For larger scale commercial work, it's a harder sell. As you've pointed out, Clojure is not hugely popular, so it's fundamentally a minority language. This can make VC's touchy about funding. This is true to the extent I'm aware of at least one organization that started moving away from Clojure for that reason.
There's also the shape of the learning curve. It can be hard to get started with Clojure because of the issues around the syntax and associated tooling. The more piecemeal aspect of the library ecosystem can then make it harder to get to hit the early successes a larger framework-oriented approach can give you out of the box. You can get there, but it at least takes more initial effort. The same is true for all the abstractive power of Clojure (and other Lisps). Abstractions are nice, but they take time to develop and the payoff is on a considerable lag. The useful rule about waiting to abstract until after you see 2 or 3 instances of a pattern means you need to at least have spent enough time to see those 2 or 3 instances (and maybe a few more) before you really start to see the payoff in your own code.
The net of all this is that it's a language that may make it more difficult to get funding, will be initially somewhat confusing to most developers, and the payoff may well be deferred to the point you don't see it before you give up (either out of frustration or due to external factors). All in all, a considerable set of headwinds.
So what does that mean? It's probably better for projects on a longer time horizon that have a team willing and able to put in extended effort to effectively use the language. (And if the team is not self-funded, good to have a funder with some ability to accept the risk of a non-conventional solution). Not saying these projects don't exist, just that they're not common enough to build a 'popular/mass-market' ecosystem on.