Official Clojure Documentary page with Video, Shownotes, and Links

Posted by adityaathalye 19 hours ago

Comments

Comment by slifin 4 hours ago

Looking back Clojure has been the best thing to happen to me in this industry

I doubled my salary using it and changed industries to much more stable industries

I've been to a lot of conferences and meet ups in my career but the feeling of joy and inclusivity at Heart of Clojure was unreal

The community is still alive and well, my favourite passionate sub culture in the Clojure community at the moment is the Jank community, building a Clojure Dialect for low level work an incredible amount of work but they're doing it anyway

The problem is businesses aren't really interested in stability integrity or joy when it comes to their languages they want to commodify their developers by forcing them to write the most popular and replaceable languages possible

Then they're surprised when the quality of developers they're able to hire drops and the quality of their software drops it's all just a race to the bottom - emboldening companies to try and replace developers with AI and destroy their own companies in the process

What surprised me the most in working with Clojure commercially is how many commercial developers did not get the ethos of the language or have watched the rich hickey talks or use the REPL, all they see is restrictions and unfamiliarity I don't know how these people got hired without a passion for the language - lots of them get promoted to run Clojure codebases

Comment by embedding-shape 3 hours ago

> What surprised me the most in working with Clojure commercially is how many commercial developers did not get the ethos of the language or have watched the rich hickey talks or use the REPL

Yeah, this continues to stick out. The amount of people I've come across who do Clojure development and restart the application (really, the JVM process, kill it and launch it again, over and over!) is way too high, considering the first "real" reason I had for moving wholesale to Clojure was a shorter feedback loop. If that's not one of your goals when moving to Clojure, I'm not sure what you're up to really.

Comment by jgalt212 3 hours ago

Yes, but without a clean REPL you can't easily be sure that your var definitions are what you think they are.

Comment by embedding-shape 2 hours ago

Sure, so once a week or so you need to restart the process if you end up like that.

What I've seen people do, is restart the process after each change like you typically do in other languages, rather than evaluating the current form...

Comment by cfiggers 2 hours ago

The thing that happens to me is that I'll get something working in the REPL, then try to deploy it and it breaks—because unbeknownst to me, I had gotten my REPL into some state where everything was working, but a cold start doesn't look the same.

Is this a skill issue? Absolutely. Do I still restart the REPL frequently (not after every def, but often) just to make sure I'm working with the same environment my program will be experiencing at run time? Yes I absolutely do.

Comment by embedding-shape 7 minutes ago

Ah yeah, been there, and probably the first time was when renaming a function but missing to update callers, so callers keep calling the old function, and you have no idea why the changes you made in the new function aren't working.

I have a this little function for clearing the current namespace that I call every time I rename any var inside a namespace:

  (defn clear-ns []
    (map #(ns-unmap *ns* %) (keys (ns-interns *ns*))))

Not a perfect solution, but personally I also don't know a better solution that doesn't involve loosing out on other (non-negotiable for me) benefits.

Comment by Folcon 1 hour ago

Couldn't you have one test that requires your -main and runs it?

Just fire that off every now and then?

Basically the same thing, but you don't lose repl state

Comment by TacticalCoder 1 hour ago

> Yes, but without a clean REPL you can't easily be sure that your var definitions are what you think they are.

vars and functions too. It's the biggest issue: the inevitable mismatch after a while.

As soon as I've got any doubt there might be a stable cache or a mismatch, I'll just "nuke the current CIDER buffers and relaunch cider-jack-in-clj&cljs". And it takes 1.3 seconds.

I'll also regularly spawn, from a terminal next to my Emacs, all the unit tests related to what I'm working on, in its own JVM / process(es). I'm not talking about running tests on commit (which I can do too). I'm not talking about running tests when I modify a function.

I was there 3000 years ago when Java 1.1 was using green threads on Linux and using Java on Linux required a serious leap of faith (but I knew... I knew it'd take the world... And I knew great things like Clojure would then come).

Now a JVM starts and exits in 40 ms.

Emacs starts and exit, with 4 000 lines of elisp customization I created over the years, in 1.1s.

I cider-jack-in-clj&cljs spawning both a CLJ and a CLJS REPL in 1.3s.

Clojure devs definitely should modify vars and redefine functions at runtime and use the REPL etc.

But there's no need to let a REPL live for one week like GP is suggesting. I can launch my entire app, including Emacs and two REPLs, in 2.5s. While at the same time having all my unit tests being launched in another process.

At 2.5s to "restart the world", there's no reason not to do it more than once a week.

P.S: also stale caches are a thing in this world. It's sad but it's simply how it is. How it's always been. Restarting the whole world, while in dev, helps also deal with a great many stale caches issues that may not be related to Clojure but to other things (e.g. I didn't invent the "disable cache" button in browsers' developer tools and there's a reason it's there).

Comment by jwr 3 hours ago

I am so thankful for Clojure. It enabled me to run a solo-founder business for the last 10 years in a sustainable and maintainable way. It allows me to manage a large complex codebase (client+server) because of low incidental complexity and the fact that the server and the client share most of the business logic code.

Also, thanks to the focus on stability and practical usage, I don't get my rug pulled out from under me every couple of years, like with so many other languages and environments. This is incredibly important and not immediately visible when "choosing a language to use", because the new shiny and the warm fuzzy are irresistible pulls. Clojure is not the new shiny and it's not the warm fuzzy, but it is your stable long-term companion for building complex software that is maintainable.

Comment by mkw5053 17 hours ago

In a previous life, I wrote Clojure every day and still look back fondly attending Clojure/Conj and sitting next to Rich Hickey and other Clojure greats at dinner.

My first startup was all Clojure. AWS only had a dozen or two products and I think we must have been the first to compile Clojure to JS and run it on Lambda in production (the only runtime was Node.js 0.10 at the time).

Anyway, I cannot wait to watch this

Comment by throwawaygod 10 hours ago

What are you using now? how do you feel about clojure now?

Comment by mkw5053 10 hours ago

I’m no longer in a professional engineering position and have a family and toddler so less time for learning about or playing with program languages. Clojure is what really made me first start thinking about programming languages and down the rabbit hole of scala and Haskell and idris and type theory books. Which are incredible and I can’t recommend more and also not remotely practical.

Comment by chii 10 hours ago

> also not remotely practical.

studying them makes you smarter, which makes you better at using the practical stuff.

Comment by TurboHaskal 7 hours ago

It also makes you bitter, at least in my experience.

Comment by xmonkee 12 hours ago

How do you feel about it now? Like holistically.

Comment by mkw5053 10 hours ago

I miss it. I’m now more removed and building software as a means to an end.

I miss it just like I miss the program language and type theory group meetups in SF and working through problems in dependently types languages like Idris and being out of my depth.

Comment by wazHFsRy 9 hours ago

I felt exactly the same, but recently started building side projects again in Haskell and fell in love again. Really brought my passion for software development back. 2026 feels perfect for that, as AI can help with things where one was stuck, not the stuck in a good learning way, forever in the past. Now is the time!

Comment by boriskourt 7 hours ago

I’ve been using Clojure since 2013, and can say that it has been an enormous positive force in my life. I’ve been a very unorthodox user, most of my artworks were built using Clojure in some way. But I’ve also worked in industry, and there I think Clojure helped me avoid burnout on more than one occasion. Especially when running a startup built half on it :)

It’s also been a privilege to participate in the community. From Clojure west to the Conj, to the online discussions. Huge thanks to everyone that’s made this possible over the decades.

Comment by ch4s3 37 minutes ago

I'm not sure what you use ti for, but your website is beautiful and your work is really striking.

Comment by pjmlp 9 hours ago

Clojure is my favourite alternative language on the JVM, besides offering what Lisps have provided for decades, their philosophy of embracing the host platform, instead of all the talk that the next JVM will be rewriten in it like some others do, makes being around Clojure folks much more appealing.

Comment by dgb23 6 hours ago

When I was younger this actually irked me a bit. I wasn't familiar with either, so it felt burdensome to me. The tooling also wasn't as good as it is now.

However there's no doubt that this is one of the primary reasons why Clojure became relevant and widely used (for a niche language). Seamless integration (or even improved integration) is very useful.

Another language that takes this approach is Zig. My intuition is that here as well, it's a unique selling point that will help with adoption and day to day usefulness.

Comment by bachmeier 1 hour ago

I've always enjoyed using Clojure. Unfortunately, most of the things I do require interacting with the C world, so it has never been a real option as my primary language.

Comment by perrygeo 52 minutes ago

You might be interested in https://jank-lang.org/ - still early days but full C/C++ interop is the plan.

Comment by erichocean 53 minutes ago

I also interact a ton with C and C++, but it's easy today to have Claude write a Project Panama wrapper and then put a nice Clojure veneer on top of the Java.

Comment by christophilus 13 hours ago

Excellent. The only thing I wish they had added was borkdude.

Comment by iLemming 13 hours ago

Yes, sad there's no European presence (unless I missed someone). There's tons of Clojure over there. Metosin, Juxt, Borkent, Gaiwan (Arne), Flexiana, Peter Strömberg (Calva), Dustin Getz (hyperfiddle/electric), Christophe Grand (ClojureDart), Bojidar (CIDER), Renzo, and many, many more.

Comment by macmac 8 hours ago

I agree. Probably a cost issue as all interviews appear to be done in person.

Comment by simongray 6 hours ago

I am pretty sure Dustin Getz is American.

Comment by ajdegol 15 hours ago

didn't know datomic was free of licensing fees - I didn't use it back in the day because the cost was prohibitive... interesting

Comment by TacticalCoder 15 hours ago

Incredible: I had not idea NuBank discovered Datomic first and that it's Datomic that led them to Clojure, 100 million+ customers, and eventually acquiring Cognitect.

Good to see David Nolen (aka "swanodette") is in the documentary too.

As a bonus here's a recent talk from David Nolen about Clojure/ClojureScript and using DOM morphing instead of React.

If you don't want to watch it all, just take two minutes to watch from 23m15s to 25m15s. He compares a behemoth slurping all the browser's CPU and RAM resources versus a 13 Kb of JavaScript + Web components and DOM morphing:

https://youtu.be/BeE00vGC36E

His talk is presented from Emacs, gotta love that too...

Comment by pgt 5 hours ago

Datomic was the reason I switched [^1] to Clojure as my primary language in 2014. It was a gamble, but it paid off in the end.

I maintain that Clojure is the best AI-first language due to the lightning-fast iteration via the nREPL and Clojure's token efficiency.

[^1]: https://petrustheron.com/posts/why-clojure.html

Comment by pjmlp 9 hours ago

Emacs has always had a tight link with Lisp communities, due to its history, including ties to Lisp Machines, so naturally many use it.

However, as someone that rather use Lispworks, Allegro, Racket, there is also Cursive on top of InteliJ.

However note that XEmacs was my IDE replacement during my first UNIX decade, due to lack of proper alternatives, so I do know about what Emacs and its derivatives are capable of, no need for yes but replies.

Comment by mkw5053 15 hours ago

I don't know if it's still the case, but at old clojure conferences, or meetups, or places of employment, emacs was a prereq and assumed (and the most enjoyable)

Comment by adityaathalye 9 hours ago

I think it was more like Emacs got Clojure development niceties early, particularly tight REPL integration.

Things have been different for well over five years --- about a third of Clojure's life. There are so many first-class options now. When teaching Clojure, I direct everybody to either VSCode + Calva, or Intellij + Cursive.

LSP has really upped the game too. I rebuilt my Emacs development workflow around LSP for all the things.

These days, I sometimes forget to fire up the REPL, because of all this fantastic "static analysis style" developer tooling by borkdude and eric dallo.

Much gratitude to all the toolsmiths from all over the Clojure ecosystem. Special shout-out to LightTable for upping the game for everybody. I was very sad when the project went dormant.

Comment by lemming 9 hours ago

Things have been different for well over five years...

In fact, I first presented Cursive at the conj 2014, and I'd been working on it in open beta for perhaps a year before that, so well over 10 years!

...all this fantastic "static analysis style" developer tooling by borkdude and eric dallo.

ahem

Comment by adityaathalye 6 hours ago

Cursive has been way ahead of the curve, yes. Sorry Colin, I'm both emacs-addled and fuzzy with timelines :D

So think of it more like "static analysis stuff for the rest of us" :D

Comment by lemming 4 hours ago

Hehe, Lisp Emacs Myopia is indeed a real thing. Cursive users have been not starting REPLs for over a decade now!

j/k of course, and no offence taken :-)

Comment by tgdhtdujeytd 13 hours ago

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Comment by agentifysh 16 hours ago

is clojure still relevant in the post agentic coding reality that opens up pretty much all esoteric languages to everyone ?

back in the day used to use clojure to write a fintech app but not sure if it is still relevant has uses vs other langs that have emerged

Comment by jwr 3 hours ago

I work on a large Clojure codebase with AI, and I'm getting excellent results. Likely factors are code density, the resulting token density, and a lot of well-architected code that the AI can follow — I'm not sure exactly, but the results are really good.

Comment by slifin 2 hours ago

Yeah I see this at work - people are sceptical that AI + Clojure even works

but in my experience its amazing the overall quality of Clojure code in the wild tends to be higher than your typical language so AI's training on Clojure tends to be on modern and high quality code and the language is very token efficient, you can also tell AI to interact with the REPL to avoid restarts

The only downside I've seen reported is mis-matched parens but for me models have been strong enough to balance parens for about a year at least it's not something I actively work-around even though there are work-arounds like brepl and others

Comment by hsaliak 14 hours ago

Clojure had lousy error messages, agents deal with this well. Clojure is capable of producing some of the most dense code I’ve ever seen, so manual code reviews really start to feel like a bottleneck unless your goal is to level up.

Comment by embedding-shape 2 hours ago

> Clojure is capable of producing some of the most dense code I’ve ever seen, so manual code reviews really start to feel like

For me it's the opposite, the dense code is easier to review, because the proposed changes are almost always smaller and more informative. Contrast a change in a typical TypeScript project where changes propagate across tens of files, that you need to jump in-between just to understand the context. In the time it takes me to ramp up understanding what the change is, I've already completed the review of a change in a Clojure program.

Comment by asa400 1 hour ago

Couldn't agree more. And I actually kind of like Typescript, but man, typical Typescript projects are so verbose and sprawling, it's crazy.

Comment by tosh 6 hours ago

I would say dense code tends to help code reviews. It just is a bit unintuitive to spend minutes looking at a page of code when you are used to take a few seconds in more verbose languages.

I find it also easier to just grab the code and interactively play with it compared to do that with 40 pages of code.

Comment by iLemming 13 hours ago

I find it actually the best substrate to write AI tooling. All my custom MCPs are written in Clojure (bb). You hook up the agent to the REPL and let it go wild - it builds something nice. Also, Clojure is one of the most token efficient PLs.

Comment by yogsototh 3 hours ago

Personally this is a hidden trick I use.

Ask AI to build something. By default it will use python. Sometimes js or typescript.

Ask then to do the same thing in Clojure. The result is generally an order of magnitude better. Shorter, easier to read for both humans and llm. Easier to adapt to changes.

Comment by embedding-shape 2 hours ago

Not to mention that changes are easier to review, because there is less of them. Same semantic diff for JavaScript and Clojure looks vastly different, and I'll favor to review Clojure changes any day of the week.

Comment by erichocean 51 minutes ago

Autochrome [0] make reviewing Clojure diffs from AI really easy.

[0] https://github.com/ladderlife/autochrome

Comment by MarkMarine 14 hours ago

One of the main problems I have with the models coding is the feedback loop is way down the chain from generation, it's out at the commit boundary for python when your hooks are running, maybe at the point where the model wants to push a PR. The REPL lets that happen during generation, and the other safety measures help immensely. Immutable data, STM, all of the features in Clojure that gave devs super powers now do the same for a model.

Comment by asa400 1 hour ago

This is like asking if violins are still relevant because we have cars now.

Comment by arikrahman 6 hours ago

I would say with the nREPL feature and letting the AI Agent jack in, Clojure may actually be the most well positioned language for this use case.

Comment by netbioserror 16 hours ago

Clojure might be the least esoteric language ever. Call a function, get a value.

Comment by agentifysh 15 hours ago

It definitely is more "mainstream" than others but I just don't see the same level of attention and enthusiasm around it anymore. I'm sure it is still being used in many places but like Elixir, hiring remains on the tough end.

Comment by iLemming 13 hours ago

Hiring good talent was always problematic. This has nothing to do with the quality, capacity, and robustness of the language or its relevance. Hiring people who would love to use Clojure but have no prior experience is not that difficult - it's just that every company wants an expert, but they don't want to offer expert salaries. In places where they do, the competition is nuts, on top of that, experienced Clojuristas typically get interviewed and scrutinized with the same level of rigor as architects.

The industry should have optimized for hiring people interested in PLs like Clojure instead of LeetCode drillers. Clojure is rarely the first, second, or even third programming language people choose to learn. It demands a specific vision, dedication, and discipline that fundamentally transforms how people think about computation, data flow, distributed systems, and concurrency. The ROI from hiring an average developer experienced in Clojure has the potential to significantly exceed that of a typical hire. Even when there's zero Clojure in prod.

Comment by acheron 11 hours ago

I've had Clojure on my resume for 10 years, mainly to see if anyone would ask about it. Nobody ever has, until an interview a couple days ago. We'll see if it actually helps in leading to an offer, I guess.

Comment by iLemming 11 hours ago

I have the opposite experience - been using Clojure for over a decade and it feels like only that mattered for the last five jobs. Even though it's really only just one of many layers that required to do the job. I honestly would love to find a non-clj team and convince them to use it. There are so many useful scripts we write in babaska alone, it just sounds wasteful not to use that path, fully knowing of its existence.

Comment by uxcolumbo 9 hours ago

Can you talk more about those scripts, what are you using it for?

Comment by yogthos 15 hours ago

Clojure is more relevant than ever in post agentic coding because of immutability and the REPL. The two big problems with agentic coding is context growing in unbounded fashion, and agents being able to get quick feedback on what they're doing. Mainstream languages fail on both accounts. I've found Clojure has been a great fit for keeping agents on track.

I've wrote about this in more detail here if you're interested https://yogthos.net/posts/2026-02-25-ai-at-scale.html

Comment by malindasp 14 hours ago

The double belt buckle is a pretty classic diffusion model artifact — it struggles with symmetrical accessories because it's essentially pattern-matching textures rather than understanding "this person is wearing one belt." Same reason you see six-fingered hands.

The repeated code on the steps is actually the more interesting tell to me. An artist would vary that deliberately for visual interest. A model just tiles what it learned looks like "code."

That said, the pencil sketch theory is compelling. Hybrid workflows where a human does the composition and an AI handles color/rendering are increasingly common, and they produce exactly this kind of uncanny result — strong underlying structure with strange surface artifacts.

Whether it is or isn't AI, the irony of a documentary about a language whose community deeply values craft and intentionality potentially using generated art for the thumbnail is at least worth a raised eyebrow. Not outrage-worthy, just... a little incongruous.

Comment by puredanger 1 hour ago

It was hand drawn by an artist. Indiana Jones (the obvious inspiration) wore two belts, one for his pants, one for his whip/holster. The code was provided by Rich.

Comment by JB024066 2 hours ago

According to the documentary group it was hand drawn:

https://www.linkedin.com/posts/cult-repo_call-us-old-fashion...

Comment by kevinten10 6 hours ago

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Comment by kevinten10 6 hours ago

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Comment by ares623 16 hours ago

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Comment by iLemming 12 hours ago

You know there's a saying in Russian, that roughly translates to: "an expert surgeon is capable of helping a bad dancer", which is on itself is a reference to another idiom: "a bad dancer always blames his own balls".

That's quickly becoming befitting for cases like this - so often people rush to blame AI without even trying to use their own reasoning. I don't know what to say, hope you find a good surgeon, because it is obvious - you're shit of a dancer.

Comment by lsh0 10 hours ago

"A good craftsman doesn't blame his tools" might be the western equivalent.

Comment by TacticalCoder 15 hours ago

The very official Clojure page in TFA links to clojure-mcp (written by the person who created figwheel: a famous ClojureScript library in the Clojure ecosystem) and other AI resources related to Clojure.

It's not because Rich doesn't want AI-generated pull-requests by people then taking credits that the Clojure community is anti-AI.

I use Claude Code CLI daily with Clojure, just not in a "write me five thousands lines of Clojure code I won't read" type of way.

Comment by mkw5053 16 hours ago

Are you watching the same thing I am? What AI slop?

Comment by Jeaye 16 hours ago

I think they mean the video thumbnail, which may or may not be AI-generated.

Comment by FelipeCortez 16 hours ago

I don't think it is, considering they highlighted it in a post about human craft [1]. I read somewhere it was illustrated by felipemelo.net, but can't find the reference anymore

[1]: https://bsky.app/profile/cultrepo.bsky.social/post/3mjhubrh3...

Comment by pixelmonkey 15 hours ago

It'll be interesting to learn whether it was AI-generated. It certainly SEEMS like it is. It has a few "tells":

- two belts and two Clojure logo belt buckles

- same code repeated on the steps (odd artistic choice if made by the artist)

- the seemingly out-of-place scarf, stylistically its color/pattern doesn't seem to fit

Either way, it seems like an homage to this Indiana Jones and the Temple of Doom poster:

https://www.slantmagazine.com/wp-content/uploads/2008/05/tem...

Comment by latexr 6 hours ago

There’s nothing odd about two belts in this situation. One is the belt for the pants and the other is the utility belt holding the pouches. You need to be able to add and remove the utilities without having your pants fall.

The weird choice is having a belt and suspenders. That only works as a fashion choice, which makes little sense for an explorer.

Comment by dmix 10 hours ago

That wouldn't be very interesting at all. It's just a thumbnail on a niche programming documentary

Comment by FelipeCortez 13 hours ago

the scarf matches the one Rich is wearing near the end of the documentary. the code matches what's on the Clojure source code, even if it's an odd choice. the two belts are in the draft, even if only one of them features the logo. the artist's instagram has a bunch of well colorized artwork. I believe it is really human made

Comment by pixelmonkey 13 hours ago

Huh. I don’t doubt you, but I guess this is a sign pervasive AI/LLM generative artwork is messing with my brain’s pattern matching at a deep level.

Comment by pixelmonkey 15 hours ago

The BlueSky post has another interesting clue. The pencil sketch on the right. Seems possible a human artist drew the sketch, then had an AI model "colorize" it. And in so doing, maybe the AI model added the 3 genAI tells/artifacts I identified above.

Comment by keychera 10 hours ago

Rich commented in one of the comments under the video pointing the same thing and he says it is not AI generated

Comment by Fitzero 10 hours ago

At least the cult repo folks said on LinkedIn that it is not, which tbh is surprising.

https://www.linkedin.com/posts/emmalouisetracey_one-of-my-fa...

Comment by agentifysh 16 hours ago

As you demonstrated, AI is not needed to write slop, just because AI is involved doesn't make it slop. We are still very much in the control even if it is generation.