Developer builds autonomous AI banking agent, learns orchestration beats model cleverness

A developer at Eko built an autonomous AI agent capable of resolving real customer support tasks against a live financial system without human intervention. The project revealed that the most critical engineering challenge is not the AI model itself, but the surrounding 'harness' — the scaffolding of orchestration loops, retry logic, error recovery, and evaluation systems. A frozen set of test cases, including scenarios the agent must never act on, gates every code change and blocks releases if safety checks regress. The team also built a self-improving research loop that monitors performance, proposes configuration changes, and only promotes them if they pass all evaluation gates. The key takeaway is that evaluation systems should be adversarial toward the code they test, ensuring safety checks cannot silently degrade over time.