A Research Preview of Codex

Some engineers on my team at Assembled and I have been a part of the alpha test of Codex, and I'll say it's been quite impressive.

We’ve long used local agents like Cursor and Claude Code, so we didn’t expect too much. But Codex shines in a few areas:

Parallel task execution: You can batch dozens of small edits (refactors, tests, boilerplate) and run them concurrently without context juggling. It's super nice to run a bunch of tasks at the same time (something that's really hard to do in Cursor, Cline, etc.)

It kind of feels like a junior engineer on steroids, you just need to point it at a file or function, specify the change, and it scaffolds out most of a PR. You still need to do a lot of work to get it production ready, but it's as if you have an infinite number of junior engineers at your disposal now all working on different things.

Model quality is good, but hard to say it's that much better than other models. In side-by-side tests with Cursor + Gemini 2.5-pro, naming, style and logic are relatively indistinguishable, so quality meets our bar but doesn’t yet exceed it.

If you aren't hiring junior engineers to do these kinds of things, where do you think the senior engineers you need in the future will come from?

My kid recently graduated from a very good school with a degree in computer science and what she's told me about the job market is scary. It seems that, relatively speaking, there's a lot of postings for senior engineers and very little for new grads.

My employer has hired recently and the flood of resumes after posting for a relatively low level position was nuts. There was just no hope of giving each candidate a fair chance and that really sucks.

My kid's classmates who did find work did it mostly through personal connections.

To be clear, we still hire engineers who are early in their careers (and we've found them to be some of the best folks on our team).

All the same principles apply as before: smart, driven, high ownership engineers make a huge difference to a company's success, and I find that the trend is even stronger now than before because of all the tools that these early career engineers have access to. Many of the folks we've hired have been able to spin up on our codebase much faster than in the past.

We're mainly helping them develop taste for what good code / good practices look like.