I disagree. Easily reviewing and combining multiple streams of parallel work is more valuable than ever.

With jj worktrees, you can even have agents working on each of those sub-megamerge branches in parallel.

I've been playing around with agent-native source annotation to specifically address the massively parallel work problem. Check it out here: https://github.com/draxl-org/draxl

You don’t need jj for this anymore. The whole premise of optimizing human workflows around source control is becoming obsolete.

When LLMs are driving development, source control stops being an active cognitive concern and becomes a passive implementation detail. The unit of work is no longer “branches” or “commits,” it’s intent. You describe what you want, the model generates, refactors, and reconciles changes across parallel streams automatically.

Parallel workstreams used to require careful coordination: rebasing, merging, conflict resolution, mental bookkeeping of state. That overhead existed because humans were the bottleneck. Once an LLM is managing the codebase, it can reason over the entire state space continuously and resolve those conflicts as part of generation, not as a separate step.

In that world, tools like jj are optimizing a layer that’s already being abstracted away. It’s similar to how no one optimizes around assembly anymore. It still exists, it still matters at a lower level, but it’s no longer where productivity is gained.

> The unit of work is no longer “branches” or “commits,”

It better be, now and going forward for people who use LLMs..because they will need it when LLM messes up and have to figure out, manually, how to resolve.

You ll need all the help (not to mention luck) you need then..

There are a lot of assumptions baked into your assessment. We are not at the point where manual workflows are obsolete. Maybe it is for folks who work on web apps, but it's certainly not the case for many others. AI Agents are constantly making mistakes and need oversight. Things have gotten dramatically better, but not enough for me to trust it to not create a terrible mess.

A lot of words to say "LLMs are good for this, trust me bro!"

You're bashing the old way, but you do not provide any concrete evidence for any of your points.

> The unit of work is no longer “branches” or “commits,” it’s intent.

Insert <astronaut meme "always has been">.

Branching is always about "I want to try to implement this thing, but I also want to quickly go back to the main task/canonical version". Committing is about I want to store this version in time with a description of the changes I made since the last commit. So both are an expression and a record of intent.

> Parallel workstreams used to require careful coordination: rebasing, merging, conflict resolution, mental bookkeeping of state.

Your choice of words is making me believe that you have a poor understanding of version control and only see it as storage of code.

Commits are notes that annotates changes, when you want to share your work, you share the changes since the last version everyone knows about alongside the notes that (should) explain those changes. But just like you take time to organize and edit your working notes for a final piece, rebasing is how you edit commits to have a cleaner history. Merging is when you want to keep the history of two branches.

Conflict resolution is a nice signal that the intent of a section of code may differ (eg. one wants blue, the other wants red). Having no conflict is not a guarantee that the code works (one reduces the size of the container, while the other increase the flow of the pipe, both wanted to speed up filling the container). So you have to inspect the code and run test afterwards.

Discard the above if you just don't care about the code that you're writing.