Working with Claude Code in hard mode

After a long time working deep in the computering mines I recently decided to drag myself kicking and screaming into the Century of the Fruitbat, and learn how to machine whisper with AI.

My explicit goal is to push beyond “vibe coding” and understand how to hold the technology for actual AI-assisted engineering.

I want to understand how AI fits into the RealWorld™ and actual software engineering work.

To find out, I decided to run in Hard Mode - using Claude Code to create a Rust Bevy 0.17 space simulation using full orbital mechanics and real physics.

What makes this “Hard Mode”

The experiment looks like this:

  1. Claude Code CLI Plus extensive collection of custom agents, commands, and skills.

  2. Bleeding edge technology Bevy 0.17. An infamously moving target that changes, sometimes radically, on a ~3-month cadence.

  3. Zero physics domain knowledge Plus full orbital mechanics.

  4. Zero game development domain knowledge Plus 3D rendering, and fragment & compute shaders

  5. Strict RealWorld™ quality standards Rigorously and relentlessly idiomatic, modular, tested, documented, and etc and etc.

Perhaps this is slightly unhinged way to evaluate the machine, but that is the point:

What better way to find out than to deliberately turn the difficulty up to 11?

Bleeding edge technology

Bevy is excellent, but it is also famous for its ruthlessly fast-moving API.

The Bevy Quick Start has a disclaimer that should strike fear into the heart of any LLM:

Bevy is still in the early stages of development… A new version of Bevy containing breaking changes to the API is released approximately once every 3 months.

Perfect.

Agents rely heavily on implicit knowledge. Pattern matching against the billions of lines of code they were trained on. Vibe coding works because the model is optimised for shovelling large volumes of code that are a very slight variation of the large volumes of code it has seen before.

When working with Bevy, the machine is always working with outdated knowledge with hilariously infuriating consequences:

  • It confidently suggests APIs that no longer exist
  • It emits syntactically correct Rust that simply doesn’t compile
  • It blends together blog posts, old examples and hallucinations into something that looks real until you hit cargo build
  • It will happily acknowledge the correct version, read the correct documentation, and promptly implement code for an imagined Bevy 0.17/16.15.14 API.

This isn’t a bug; it’s the default state when you put a probabilistic model on an unstable stack.

Hard mode means: the model is (nearly) always wrong

Zero domain knowledge

Domain knowledge

  • physics: nope
  • games: nope

I don’t know any physics. I don’t know anything about game development. (Note: I do know Rust, and have been Rusting in production for a couple of years).

Zero domain knowledge means:

  • I have no prior knowledge of any physics concepts
  • I have no understanding of any of the math(s) involved
  • I have no intuition for the orbital calculations
  • I have no mental model for how game rendering pipelines are usually structured
  • I have minimal understanding of what makes an idiomatic Bevy application

I can’t help the machine. I have zero implicit knowledge that I can rely on to shape context. I have no intuition that the output is good, or yet another delivery of HallucinatedHotMess™.

Hard mode means: the model is (nearly) always wrong, but I don’t know if it is wrong

To infinity and beyond

I am trying to answer the question: What even is AI-assisted engineering in this, the Century of the Fruitbat, CE 2025?

Hard mode is an experiment. A lab.

  1. Pick a hard, unstable stack (Bevy 0.17 + orbital mechanics)
  2. Enforce rigorous RealWorld™ quality standards
  3. Use the machine for AI-assisted collaboration and engineering
  4. Discover and refine our machine-whispering techniques and processes

I have spent a long career working deep in the computering mines, shovelling code by hand. It is time to embrace the machine-powered TurboShovel™.

Maybe it works. Maybe it doesn’t. Either way, I want more than “vibes”.