Brex faced significant challenges in 2024, cutting 20% of its workforce as growth stalled amid rising competition. However, by 2025, it made a remarkable comeback, surpassing $500 million in annualized revenue and expanding into Europe. A key factor in this turnaround was Brex's aggressive shift toward AI integration across its operations. CTO James Reggio emphasized a culture of AI fluency, which included modernizing the tech stack and employing AI agents to improve efficiency. Brex's team structure evolved to support this shift. After laying off 282 employees, the company flattened its hierarchy and streamlined its focus on a unified roadmap. The current team includes around 300 engineers and 350 in product, design, and engineering roles. A specialized team focused on large language models (LLMs) operates like a startup, working long hours but growing slowly to maintain agility. Brex encourages broad AI adoption, providing access to multiple AI tools without restricting choices, thereby enabling employees to find the solutions that work best for them. To facilitate AI fluency, Brex implemented an organization-wide training program that categorizes employees into fluency levels to tailor project assignments. This training isn’t punitive but serves as a way to motivate employees to leverage AI tools. The hiring process has also shifted, focusing on candidates' AI fluency through practical, on-site projects rather than traditional coding tests. Brex's "Quitters Welcome" initiative actively seeks out talent who might eventually start their own companies, positioning itself as a training ground for future founders while emphasizing a meritocratic culture.