Django: what’s new in 6.0

You are a great writer - thanks for putting this together!

> The Many Problems with Celery:

— https://steve.dignam.xyz/2023/05/20/many-problems-with-celer...

> The problems with (Python’s) Celery:

— https://docs.hatchet.run/blog/problems-with-celery

> Dramatiq motivation:

— https://dramatiq.io/motivation.html

Here are some alternatives:

Dramatiq: https://github.com/Bogdanp/dramatiq

RQ: https://github.com/rq/rq

Huey: https://github.com/coleifer/huey

Hatchet: https://github.com/hatchet-dev/hatchet

It's okay till it's not. Everyone I know who had Celery in production was looking for a substitution (custom or third-party) on a regular basis. Too many moving pieces and nuances (config × logic × backend), too many unresolved problems deep in its core (we've seen some ghosts you can't debug), too much of a codebase to understand or hack. At some point we were able to stabilize it (a bunch of magic tricks and patches) and froze every related piece; it worked well under pressure (thanks, RabbitMQ).

Celery is great and awful at the same time. In particular, because it is many Python folks' first introduction to distributed task processing and all the things that can go wrong with it. Not to mention, debugging can be a nightmare. Some examples:

- your function arguments aren't serializable - your side effects (e.g. database writes) aren't idempotent - discovering what backpressure is and that you need it - losing queued tasks during deployment / non-compatible code changes

There's also some stuff particular to celery's runtime model that makes it incredibly prone to memory leaks and other fun stuff.

Honestly, it's a great education.

Because it’s a seducer. It does what you need to do and you two are happy together. So you shower more tasks on Celery and it becomes cold and non-responsive at random times.

And debugging is a pain in the ass. Most places I’ve been that have it, I’ve tried to sell them on adding Flower to give better insight and everyone thinks that’s a very good idea but there isn’t time because we need to debug these inscrutable Celery issues.

https://flower.readthedocs.io/en/latest/

With that logic, the Django orm should only support one database.

Exactly. There are a few libraries to achieve a similar thing in Python:

* https://htpy.dev/

* https://pypi.org/project/fast_html/

* https://fastht.ml/ (different to above, I think)

* https://github.com/volfpeter/fasthx

Probably others. I strongly prefer this to templating, but I find it makes dyed in the wool Django people squirm.

Check out the HTMX example in the blog, this helped me better understand how it could be used

https://adamj.eu/tech/2025/12/03/django-whats-new-6.0/#rende...

It's just syntactic sugar, making life a bit easier for HTMX users (cf. "htmx was the main motivation for this feature").

I'm using Unpoly and I just render the whole page and let Unpoly swap the content according to the target selectors, so no need for this. Not much difference in perf if you dont generate gigantic pages with heavy header/footer.

Partialdef inline is the real win. Lets you define parts of a page without needing to place them in another file. Reduces the mental overhead of imagining how the inclusion will look because it’s already there.

The use case is mainly driven by htmx where you will have lots of these partials and the view code renders them as individual responses.

How is it different from include? Just less files from my perspective

https://django-cotton.com/ is component-based. I used it a bit, it's nice if you're used to the ways of front-end frameworks, I guess.

I mean, it is sad. But unfortunately that is what happened with "master", "slave", "whitelist", and "blacklist". No reasonable person construed these as offensive or having any implications about the wider world. But there are people in our profession who are determined to take offense where none is given, and unfortunately they got their way.

In the US they spell it as nonze.

That didn't stop people from throwing a fit over master-slave terminology in software (having nothing to do with slavery), going so far as to rename long-standing development branch names, as well as put significant effort into removing such terms from the code itself and any documentation.