Context engineering has emerged as one of the most critical skills in working with large language models (LLMs). While much attention has been paid to prompt engineering, the art and science of managing context-i.e., the information the model has access to when generating responses-often determines the difference between mediocre and exceptional AI applications. After years of building with LLMs, we've learned that context isn't just about stuffing as much information as possible into a prompt.
For developers considering the leap from Claude Code to Codex CLI, this shift represents more than just a change in tools, it's a rethinking of how you approach workflows, task execution, and even problem-solving. With its impressive 272K token context window and open source adaptability, Codex CLI offers a tantalizing glimpse into what's possible. But before you make the switch, it's essential to understand the trade-offs and challenges that come with this upgrade.