It does use the jobs system - it should be commented so you can see what's going on!
There are actually no gameobjects at all, so pooling isn't needed. The bullets are all rendered with one draw call per bullet manager, it's about as optimised as I can make it at the minute. It should be ok with around 20,000 bullets on-screen and stay above 60fps 😁 obviously you'll never need that many, but it means you've got a lot of performance budget for other things like post-processing.
You're welcome to have a look and see how it works - that's half the reason I've put it up here and made sure it's so well commented 😂