Endava, a global software contracting firm with engineers across Europe, the Americas, and Asia, has been an early adopter of Codex. For a business built around shipping quality software for banks, insurers, retailers, and media companies, the improvements have been substantial.

“We went from producing a lot of the code ourselves to now overseeing the work that Codex can produce,” says Joe Dunleavy, Endava’s regional CTO for Europe. “The quality of output has just gone up exponentially.”

Endava now calls itself an agentic organization: a company where senior expertise is codified into agents that work alongside teams across the entire client engagement lifecycle, from intake to ideation and, finally, delivery.

Codex changes how senior and junior engineers work together, says Mike Krolnik, Endava’s Global SVP of Agentic Architecture. “Senior architects like myself, coming from complex environments, are able to articulate what we want, and Codex makes that an accessible piece of information for the more junior people on the team. And from the junior perspective, they’re able to adopt this tool and create senior, mature-level outputs.”

In practice, that means giving junior developers work that would normally be reserved for senior engineers, with Codex acting as a guide on best practices and architectural decisions. “I can give Codex a point of view, and when they’re working, it will help them understand this point of view,” Krolnik explains. “They can ask questions about things they don’t understand. As a learning tool during development, I’m able to take my experience, codify it, and have Codex work with the team to teach them better practices in software architecture and development.”

This knowledge transfer ends up being one of the core values and advantages of an agentic organization. Senior judgment, which normally comes through years of pairing, code review, and mentoring, becomes something a team can work alongside in real time. This changes how mentorship can happen for an organization’s junior developers. A single senior’s perspective, encoded into Codex, can guide multiple less-seasoned teams in parallel.

When senior judgment is always available, every step of delivery can be improved. Endava no longer treats analysis, design, and build as sequential stages handed off between specialists. “Each of these stages used to take days or weeks of analysis,” Krolnik says. “Now with Codex packaging together analysis, design, and build, we can do that as a single unified tool.”

A recent cross-team engagement shows what that looks like in practice. Endava’s legal team brought engineering a complex problem: thousands of pages of contracts to review against a specific set of criteria. Translating what the lawyers needed into something engineering could build against would normally take weeks of back-and-forth. Instead, Krolnik’s team recorded a two-hour deep-dive meeting with the legal stakeholders, fed the transcript to Codex, and used it to generate a working requirements specification. What could have taken a week or two of revision was compressed into two one-hour meetings and produced a usable spec.

The same time-saving is also showing up in client work. Endava’s teams now produce design documents, diagrams, and specifications live in client sessions to illustrate ideas. “You can tell it to draw a diagram of the proposed software architecture so it’s easier to understand for our clients,” Krolnik says. “It rapidly accelerates the back-and-forth, and it really opens a lot of doors.”

• Codify your seniors. The largest leverage comes from capturing senior architects’ judgment in Codex, so junior team members get senior guidance as they execute.
• Treat Codex as a desktop agent, not a coding assistant. The biggest unlocks at Endava came from applying Codex to requirements, design, client communication, and operations alongside code.
• Don’t just think about it, really try it! “The first piece of advice is you need to get beyond thinking about what you want to do and actually get in and try it,” Dunleavy says. Endava’s advice to teams just starting out: Pick a non-coding workflow first: requirements analysis, design documentation, or client communication. The fastest way to see Codex’s full value is to use it in a place where your team has never used a coding tool before.