Three weeks ago, Calvin French-Owen, a pivotal engineer in the development of OpenAI's groundbreaking programming agent Codex, made public his departure. In a thought-provoking blog post, French-Owen offered a glimpse into his year-long journey with the Codex project, which strives to rival advanced tools such as Cursor and Anthropic's Claude Code. He disclosed that the journey to create Codex was marked by rigorous and intense sprint phases, pushing the team to their limits.