Simplex Uses Codex to Slash Dev Time by 70%

Simplex, a technology partner specializing in consulting and systems development, has been rigorously measuring how generative AI can boost productivity. After launching a center of excellence in 2023, they adopted ChatGPT Enterprise and Codex across the organization. The results are striking: developing each screen takes 70% less time, design is 40% faster, and internal integration testing is 17% quicker. Codex isn’t just for coding—Simplex uses it for design, testing, and even automated workflows. The key insight here is that Simplex treats Codex as a primary coding agent, not just an assistive tool, allowing them to standardize knowledge and scale AI-native processes. Why it matters: This case study shows that moving beyond AI as a helper to using it as a core workflow driver can produce measurable efficiency gains, signaling a potential industry shift toward agentic development models.