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Bridging Elixir and Python with Oban

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Kaliboy4 minutes ago

This is a similar concept to Faktory, which uses a built in Redis server to manage shared job state.

You then implement workers in your language of choice and subscribe to queues.

Very interesting though, the article mentioned a few things I hadn't considered before like shared access to one database from multiple (different) apps.

I wonder how database schema state is handled in a case like that. And CI/CD.

ananthakumaran4 hours ago

We have a similar use case. All Elixir code base, but need to use Python for ML libraries. We decided to use IPC. Elixir will spawn a process and communicate over stdio. https://github.com/akash-akya/ex_cmd makes it a breeze to stream stdin and stdout. This also has the added benefit of keeping the Python side completely stateless and keeping all the domain logic on the Elixir side. Spawning a process might be slower compared to enqueuing a job, but in our case the job usually takes long enough to make it irrelevant.

kzemek8 minutes ago

We also had a similar use case, so I built Snex[0] - specifically for Elixir-Python interop. Elixir-side spawns interpreters with Ports managed by GenServers, Python-side has a thin asyncio runtime to run arbitrary user code. Declarative environments (uv), optimized serde with language-specific objects (like `%MapSet{}` <-> `set`), etc. Interpreters are meant to be long lived, so you pay for initialization once.

It's a very different approach than ex_cmd, as it's not really focused on the "streaming data" use case. Mine is a very command/reply oriented approach, though the commands can flow both ways (calling BEAM modules from Python). The assumption is that big data is passed around out of band; I may have to revisit that.

[0]: https://github.com/kzemek/snex

Kaliboy15 minutes ago

Honestly you saved yourself major possible headaches down the line with this approach.

At my work we run a fairly large webshop and have a ridiculous number of jobs running at all times. At this point most are running in Sidekiq, but a sizeable portion remain in Resque simply because it does just that, start a process.

Resque workers start by creating a fork, and that becomes the actual worker.

So when you allocate half your available RAM for the job, its all discarded and returned to the OS, which is FANTASTIC.

Sidekiq, and most job queues uses threads which is great, but all RAM allocated to the process stays allocated, and generally unused. Especially if you're using malloc it's especially bad. We used jemalloc for a while which helped since it allocates memory better for multithreaded applications, but easiest is to just create a process.

I don't know how memory intensive ML is, what generally screwed us over was image processing (ImageMagick and its many memory leaks) and... large CSV files. Yeah come to think of it, you made an excellent architectural choice.

barrell2 hours ago

Similar use case as well. I use erl ports to spawn a python process as well. Error handling is a mess, but using python as a short scripting language and elixir for all the database/application/architecture has been very ideal

dnautics3 hours ago

I have one vibecoded ml pipeline now and I'm strongly considering just clauding it into Nx so I can ditch the python

flippant2 hours ago

I did exactly this in early 2025 with a small keyword tagging pipeline.

You may run into some issues with Docker and native deps once you get to production. Don’t forget to cache the bumblebee files.

markstos3 hours ago

Is this part of a web server or some other system where you could end up spawning N python processes instead of 1 at a time?

ananthakumaran16 minutes ago

No, it's a background job. We can easily control the Python process count by controlling the job queue concurrency on the Elixir side.

rozap2 hours ago

I use a similar strategy for python calls from elixir. This is in a web server, usually they're part of a process pool. So we start up N workers and they hang out and answer requests when needed. I just have an rpc abstraction that handles all the fiddly bits. The two sides pass erlang terms back and forth. Pretty simple.

rekoros2 hours ago

Oban is great!

cpursley6 hours ago

Very nice, Oban is great. I effectually found a similar approach with pgflow.dev (built around pgmq) - but the stateless deno "workers" are pretty unreliable and built an elixir worker (https://github.com/agoodway/pgflow) that can pick up and process jobs that were created by pgflow's supabase/typescript client. So maybe there's an opportunity also with Oban to have a TypeScript/Node client that can insert jobs that Elixir/Python Oban can pick up. Also, I wonder if another approach vs the python workers picking things up is to have elixir workers call/run python/lua, etc code or is that too limiting?

elitepleb6 hours ago
cpursley6 hours ago

btw, a lot of postgres envs are not going to have pgmq, so just use Oban and don't reinvent the wheel like I did ;)

nimbus-hn-test4 hours ago

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mrcwinn3 hours ago

I absolutely love Elixir, but if this is the bridge you need to cross, just write it in Python in the first place.

dnautics3 hours ago

It's 2026 and the LLMs score high on elixir, just write it in python and patch it over to elixir gradually

Towaway693 hours ago

Or patch it over to python, I assume LLMs are even better at python.

dnautics3 hours ago

Don't assume. Empirically, they are not. (This post Feb 2026 may change in future yadda yadda)

See: autocodebench

https://github.com/Tencent-Hunyuan/AutoCodeBenchmark/tree/ma...

+4
Towaway693 hours ago
jongjong4 hours ago

I don't see the point of Elixir now. LLMs work better with mainstream languages which make up a bigger portion of their training set.

I don't see the point of TypeScript either, I can make the LLM output JavaScript and the tokens saved not having to add types can be used to write additional tests...

The aesthetics or safety features of the languages no longer matter IMO. Succinctness, functionality and popularity of the language are now much more important factors.

HorizonXP4 hours ago

So I know these are just benchmarks, but apparently Elixir is one of the best languages to use with AI, despite having a smaller training dataset: https://www.youtube.com/watch?v=iV1EcfZSdCM and https://github.com/Tencent-Hunyuan/AutoCodeBenchmark/tree/ma...

Furthermore, it's actually kind of annoying that the LLMs are not better than us, and still benefit from having code properly typed, well-architected, and split into modules/files. I was lamenting this fact the other day; the only reason we moved away from Assembly and BASIC, using GOTOs in a single huge file was because us humans needed the organization to help us maintain context. Turns out, because of how they're trained, so do the LLMs.

So TypeScript types and tests actually do help a lot, simply because they're deterministic guardrails that the LLM can use to check its work and be steered to producing code that actually works.

dnautics3 hours ago

I don't think LLMs benefit from having code properly typed (at the call definition). It's costly to have to check a possibly remote file to check. The LLM should be able to intuit what the types are at the callsite and elixir has ~strong conventions that LLMs probably take advantage of

baseonmars2 hours ago

llms benefit greatly from feedback and typing/type errors are one of the fastest and easiest methods of feedback to give to an llm.

dnautics2 hours ago

Think about fitts law: the fastest place to click under a cursor is the location of the cursor. For an LLM the least context-expensive feedback is no feedback at all.

I think codebases that are strongly typed sometimes have bad habits that "you can get away with" because of the typing and feedback loops, the LLM has learned this.

https://x.com/neogoose_btw/status/2023902379440304452?s=61

cloud84213 hours ago

> I don't see the point of Elixir now. LLMs work better with mainstream languages which make up a bigger portion of their training set.

I can't say if it works better with other languages, but I can definitely say both Opus and Codex work really well with Elixir. I work on a fairly large application and they consistently produce well structured working code, and are able to review existing code to find issues that are very easy to miss.

The LLM needs guidance around general patterns, e.g. "Let's use a state machine to implement this functionality" but it writes code that uses language idioms, leverages immutability and concurrency, and generally speaking it's much better than any first pass that I would manually do.

I have my ethical concerns, but it would be foolish of me to state that it works poorly - if anything it makes me question my own abilities and focus in comparison (which is a whole different topic).

jakejohnson3 hours ago

LLMs work great with Elixir. Running tsc in a loop while generating code still catches type errors introduced by an LLM and it’s faster than generating additional tests. Elixir is also succinct and highly functional. If you can’t find a specific library it’s easier than ever to build out the barebones functionality you need yourself or use NIFs, ports, etc.

https://dashbit.co/blog/why-elixir-best-language-for-ai

dnautics2 hours ago

> Succinctness, functionality and popularity of the language are now much more important factors.

No. I would argue that popularity per se is irrelevant: if there are a billion examples of crap code, the LLMs learn crap code. conversely know only 250 documents can poison an LLM independent if model size. [Cite anthropic paper here].

The most important thing is conserve context. Succinctness is not really what you want because most context is burned on thinking and tool calls (I think) and not codegen.

Here is what I think is not important: strong typing, it requires a tool call anyways to fetch the type.

Here is what I think is important:

- fewer footguns - great testing (and great testing examples) - strong language conventions (local indicators for types, argument order conventions, etc) - no weird shit like __init__.py that could do literally anything invisible to the standard code flow

techpression2 hours ago

Your code doesn’t run anywhere? Running on the BEAM is extremely helpful for a lot of things. Also, I review my LLM output, I want that experience to be enjoyable.

WolfeReader3 hours ago

I'm starting to see a new genre of post here in the AI bubble, where people go to topics that aren't about AI at all, and comment something like, "this doesn't matter because it's not AI". This is the third I've seen in a week.

languagehacker4 hours ago

I feel like if you need to utilize a tool like this, odds are pretty good you may have picked the Wrong Tool For the Job, or, perhaps even worse, the wrong architecture.

This is why it's so important to do lots of engineering before writing the first line of code on a project. It helps keep you from choosing a tool set or architecture out of preference and keeps you honest about the capabilities you need and how your system should be organized.

Arubis4 hours ago

It’s almost as though choosing a single-threaded, GIL-encumbered interpreted scripting language as the primary interface to an ecosystem of extremely parallelized and concurrent high-performance hardware-dependent operations wasn’t quite the right move for our industry.

markstos2 hours ago

Ha. The question now is whether the ML industry will change directions or if the momentum of Python is a runaway train.

I can't guess. Perl was once the "800-pound gorilla" of web development, but that chapter has long been closed. Python on the other hand has only gained traction since that time.

markstos3 hours ago

Sometimes the "right tool for the job" philosophy leads to breaking down a larger problem into two small problems, each which has a different "right tool".

Choosing a single tool that tries to solve every single problem can lead to its own problems.

victorbjorklund4 hours ago

Strange opinion. Plenty of apps have more than one language. I might end up using this.

Why? Because my app is built in Elixir and right now I’m also using a python app that is open source but I really just need a small part of the python app. I don’t wanna rewrite everything in Elixir because while it’s small I expect it to change over time (basically fetching a lot of data sources) and it will be pain to keep rewriting it when data collections needs to change (over a 100 different sources). Right now I run the python app as an api but it’s just so overkill and harder to manage vs just handling everything except the actually data collection in Elixir where I am already using Oban.

geooff_4 hours ago

I disagree, using python for a web-server and something like celery for background work is a pretty common pattern.

My reading of this is it more or less allows you to use Postgres (which you're likely already using as your DB) for the task orchestration backend. And it comes with a cool UI.

languagehacker4 hours ago

That's not the sort of architecture I'm referring to. I'm specifically talking about splitting your application layer between Elixir and Python.

whalesalad4 hours ago

What leads you to this conclusion