Official Clojure Documentary page with Video, Shownotes, and Links

by adityaathalye • 3 months ago

362 105 3 months ago

mkw50536• 3 months 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

xmonkee• 3 months ago

How do you feel about it now? Like holistically.

mkw50536• 3 months 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.

LandR2• 3 months ago

I love the clojure, but I think a big downside is not being able to use it at work and now work feels like I'm being forced to work with stone age tools in comparison. That gets quite depressing sometimes.

Sometimes I think I was happier before I learned Clojure.

Ignorance was bliss.

throwawaygod2• 3 months ago

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

mkw50536• 3 months 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.

LandR2• 3 months ago

I love the clojure, but I think a big downside is not being able to use it at work and now work feels like I'm being forced to work with stone age tools in comparison.

Sometimes I think I was happier before I learned Clojure.

agentifysh2• 3 months 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

netbioserror• 3 months ago

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

agentifysh2• 3 months 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.

yogthos• 3 months 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

MarkMarine• 3 months 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.

hsaliak• 3 months 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.

tosh• 3 months 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.

embedding-shape7• 3 months 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.

iLemming12• 3 months 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.

arikrahman• 3 months 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.

jwr3• 3 months 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.

slifin2• 3 months 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

yogsototh• 3 months 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.

embedding-shape7• 3 months 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.

asa4002• 3 months ago

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

TacticalCoder2• 3 months 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...

mkw50536• 3 months 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)

adityaathalye2• 3 months 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.

pjmlp2• 3 months 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.

pgt• 3 months 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

ajdegol• 3 months 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

dimitar• 3 months ago

It is!

And also it has inspired a few other clojure datalog databases, so there is much more choice: * https://github.com/datalevin/datalevin * https://github.com/replikativ/datahike * https://github.com/threatgrid/asami

There is also xtdb, but it abandoned datalog and is going in another (albeit interesting direction) https://xtdb.com/

here is a comparison website, but it is somewhat out of date: https://clojurelog.github.io/

malindasp• 3 months 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.

JB024066• 3 months ago

According to the documentary group it was hand drawn:

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

puredanger• 3 months 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.

christophilus• 3 months ago

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

iLemming12• 3 months 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.

macmac• 3 months ago

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

simongray• 3 months ago

I am pretty sure Dustin Getz is American.

wink2• 3 months ago

Oh wow, that's indeed a bit weird.

pjmlp2• 3 months 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.

dgb23• 3 months 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.

boriskourt3• 3 months 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.

ch4s33• 3 months ago

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

boriskourt3• 3 months ago

Thank you! I’ve managed to shoehorn Clojure into everything from 3D model generation to VR networking servers for installations :D It makes so many things easier to reason about!

slifin2• 3 months 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

embedding-shape7• 3 months 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.

jgalt212• 3 months ago

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

eduction• 3 months ago

I'm probably not the sort of person you're referring to, but I do regularly restart the REPL because

1. multimethods, if you change the dispatch fn you can't get it just with a recompile, there are tools to help with this but i'm not yet in the hang of using them after several years. (Many people don't hit this because they don't use multimethods. I love multimethods for the use cases I've hit so far with clojure.)

2. interceptors (pedestal) - I love this pattern and lib, and they've made moves toward improving repl friendliness, but I find I need to recompile two NSes typically to get a true reload even in dev mode (the one where my routes are defined and the one where a particular interceptor chain is defined). sometimes i lose track of what i've reloaded, and I dont know if a bug is "real" or just an artifact of forgetting to recompile - "f it, just restart the repl"

spopejoy• 3 months ago

Been over a decade since I used Clojure in anger, but at the time it really seemed like IDEs made it hard to use a REPL with a large codebase -- they seemed more to want it to be like a javac/maven stack. I assume that got better?

ouraf• 3 months ago

Guess you could say it helped you find some clojure

jwr3• 3 months 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.

bachmeier• 3 months 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.

erichocean2• 3 months 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.

perrygeo• 3 months ago

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

andersmurphy• 3 months ago

Coffi [1] built on java 22 (project panama) C FFI. Makes binding to C from Clojure a lot of fun.

- [1] https://github.com/IGJoshua/coffi

smartmic• 3 months ago

Have a look at Janet. It is not as powerful as Clojure but for smaller projects, prototyping, scripting etc., it is really enjoyable.

https://janet-lang.org/

Unsponsoredio• 3 months ago

the "stable long-term companion" framing from jwr's comment is the part that sticks with me. every company I've worked with that chased the new shiny ended up spending more time on migrations than on the actual product.

stability is boring to talk about but it's the thing that actually lets small teams survive long enough to win.

mark_l_watson3• 3 months ago

Clojure is a great language and ecosystem. I donated a little money to Rich's efforts in the early days (I loved his older Common Lisp - Java bridge so his Clojure project was immediately interesting) and I have been paid for a few years of Clojure development.

I like maintaining the history in one place, nicely done.

I don't use Clojure much anymore, but two hours ago I updated two chapters in my old Clojure book because the examples had 'gone stale' and that was fun.

uxcolumbo6• 3 months ago

What made you stop using Clojure or not so much anymore? No jobs in Clojure?

Also, in your view, is Clojure better suited for ML / AI apps? And if so, what is stopping it from being more widely adopted. I read the interop with Python ML libraries is good?

iLemming12• 3 months ago

what is stopping it from being more widely adopted.

The best tools usually need a level of skill or patience that most developers just don't have time for. And companies have to ship with the developers they actually have, not ideal ones.

Lisp, formal methods, immutability, property-based testing - we agree on these. They just demand more than most people can give under a real deadline. A tool that shines in expert hands but falls flat for everyone else will lose to a tool that's just okay for everybody. Every time. That's basically what "worse is better" means.

In our industry we tend to approach things with "scientific methods", without actually using scientific methodology. Nobody experiments developing a real business solution with multiple teams using completely different set of tools just to see which one proves to have better ROI. What we do instead is that we go to forums and emotionally "mansplain" our anecdotal, subjective feelings about a tool or technique. Anecdotes aren't completely worthless; they're low-quality evidence, which is different. A senior engineer saying "every time I've seen a team adopt microservices before they had the operational maturity, it ended badly" is transmitting pattern-recognition from, say, fifteen projects. That's not a randomized controlled trial, but it's also not nothing. But there's flood of "unfalsifiable anecdotes" - claims structured so that any counterexample gets explained away ("you weren't doing real TDD...").

Rich Hickey's talks are not science - they're argument from principles, with illustrative examples. But they're honest about being that. He doesn't pretend to have benchmarks proving immutability is better; he reasons about it from costs and trade-offs and lets you decide. That's a legitimate mode of technical discourse. Contrast with someone claiming "studies show" functional programming reduces defects by 40%, citing one paper with n=12 undergraduates. The second is worse, and it's worse specifically because it's pretending to be scientific while the first isn't. I think the solution is not to make the field more rigorous and more scientific and require solid peer-reviewing of every idea. It's making the field more honest about the kind of claims we make.

Clojure remains hard sell to beginners because they haven't suffered enough yet. Experienced engineers get excited about immutable data because they've spent nights debugging race conditions. They appreciate simple functions-and-data because they've been lost in a tangled class hierarchy. The language solves problems they've actually had. Junior devs haven't hit those walls yet, so the solutions feel pointless. Why would you care about a painkiller if nothing hurts?

mark_l_watson3• 3 months ago

I used tools that I was paid to use. After being deep in neural networks in the 1980s, ten years ago I dropped back into deep learning, thus mostly used Python.

mkw50536• 3 months ago

Hey other Mark Watson ( ^_^)／

zerr• 3 months ago

Interesting, how many ex-users of Clojure are in the comments. Everyone is praising it, but also everyone moved to something else?

moomin3• 3 months ago

It’s a real statistical outlier, nearly every language people have moved on from gets negative reviews. Me, it was fun but it wasn’t for me and eventually I concluded a number of the fundamental design decisions were wrong.

uxcolumbo6• 3 months ago

Can elaborate which design decisions were wrong and why in your view?

throwawaygod2• 3 months ago

Can you expand on that a bit? What language do you use now?

wink2• 3 months ago

Less ex-user, more like: never really managed to get to use it at work I guess (just like it is for me). It is still a niche language (compared to the big ones) after all.

Official Clojure Documentary page with Video, Shownotes, and Links

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