AI coding agents are blowing through budgets — Replit, Kilo Code, and Symbotic explain how they're managing it

At Kilo Code, engineers are reading or writing code themselves only about 1% of the time now, according to co-founder Emilie Schario — the rest is agents. That shift is forcing new questions onto dev teams: which systems are safe to hand over, who cleans up when models goof up, how to support multi-model architectures, and whether skyrocketing token bills mean real progress or just burned IT budget.As far as tech leads from Replit, Kilo Code, and Symbotic are concerned, it’s a natural — and welcome — evolution as agentic AI becomes embedded into more and more enterprise workflows. “Unless something's really broken or debugging, 99% of the time engineers are not reading or writing code anymore,” Emilie Schario, co-founder of Kilo Code, said at VB Transform 2026. AI good at greenfield, not so great at brownfieldFor Jared Go, distinguished engineer for AI and cloud at warehouse automation company Symbotic, the current moment is about directing the focus of AI. "These are my criteria," he said. "Let's look at it from the lens of security, elegance, clean, concise code, water tightness." That way, AI does most of the heavy lifting, and human code review isn't as critical.Human involvement becomes necessary further down the line, Go noted, because agents don't make strong product decisions. “Greenfield [building brand new codebases] is so easy for agents. Brownfield [writing, updating, or maintaining existing code] we all know is where the actual challenge lies.” Replit takes a bit of a different tack: While the company has "gone very agentic," they've been more conservative with AI coding, explained Amol Jain, head of product engineering. An agent reviews each pull request (PR) and assigns it a risk score; low-risk PRs are self-merged by their author, while others go to human reviewers who read the code and give feedback.“The idea was human on the loop, not human in the loop,” Jain said. Replit’s internal tool is essentially self-driving for software engineers; devs give a task to agents, which do end to end planning, implementation, and testing. “It's a fleet of agents that run in their own cloud virtual machines (VMs) with access controls behind token proxies so they're secure,” Jain said. He shared one example where an engineer couldn’t repro or solve a “very gnarly bug” deep in its systems. It was sent to an AI manager agent, which told it to go to sleep. The manager agent then spun up a bunch of underlying agents that found the issue; it subsequently spun up a bunch more agents that found the fix. Six hours later, AI had a PR ready for the bug that had puzzled human engineers. Multi-model is the future AI providers are also evolving beyond the lock-in model, as customers increasingly demand multi-model choice. Kilo Code, for its part, supports 500-plus models in its gateway. "Your software that you're using to do agentic engineering should be decoupled from the model that you're using to do it," Schario said.For instance, Schario said companies often use expensive frontier-tier models to architect a project, then switch to a less expensive open-weight model for the rest of the work.It’s also important to respect model provider limitations, such as when they need to work in closed or isolated environments or providers in their specific regions. “It's factoring in what's important to you, what limitations you've set, what data retention policies you've established, what keys you've brought in, what commits you might have … into that routing decision,” Schario said. Replit, similarly, tends to have a better sense of the cost versus capability spectrum than its customers, Jain contended. “We are essentially making the decisions on users' behalf of what model to use when, in what capacity, to minimize cost and maximize capability.”To tokenmaxx or not to tokenmaxxOf course, an important consideration as AI adoption increases is runaway costs, which has led to