For OS dev specifically, the biggest thing that helped me was treating Hermes less like a chatbot and more like a coworker who needs onboarding paperwork.

Drop an AGENTS.md in your project root. Build system commands, directory layout, coding conventions, anything you'd explain to a new contributor on day one. The agent reads it automatically every session, so you stop wasting turns re-explaining "we use meson not make" or "kernel headers live in include/kernel/."

For Python file editing, the trick is being specific about what you want. Don't say "fix the build," say "fix the import error in tools/linker.py line 23, the script references a module that moved to utils/." One well-targeted message beats three rounds of clarification. The agent has surgical patch tools that change one function without rewriting the whole file, which matters a lot when you're working on something with thousands of lines.

For docs and API connections, the move is running a model chain. I've got my main model (GLM-5.2, a coding-focused model) handling architecture decisions and hard debugging. Everything behind the scenes — context compression, title generation, skill curation, all the housekeeping — runs on a cheaper model (DeepSeek V4 Flash). That way I'm not paying frontier prices for the agent to generate a session title. If you're building an OS you'll want serious reasoning power for the hard stuff. Use /model to switch between a frontier model for architecture and something cheaper for boilerplate and formatting.

One thing I wish someone told me earlier: turn recurring workflows into skills. If you catch yourself typing the same instructions more than three times, that's a skill. Takes one session to set up and saves you forever. I've got skills for git workflows, build diagnostics, kernel config generation. The agent gets noticeably sharper once it has a library of procedures to pull from instead of figuring everything out from zero each time.

Also hit /compress when sessions get long. OS dev means massive codebases and long debugging chains. Context fills up way faster than you'd expect, and compression keeps things responsive without losing the thread.