Building Deep Research: How we Achieved State of the Art

Research agents are rapidly becoming one of the most important applications of AI. Research is a foundational knowledge-work task: collecting, reading, and synthesizing information underpins everything from writing and decision-making to coding itself. Yet human-driven research is constrained by memory, reading speed, and time. AI research agents, by contrast, can process vast amounts of information, synthesize insights instantly, and scale effortlessly. Because of this, research agents are emerging as a top use case for AI today and will soon become a core subcomponent of broader agentic workflows across content generation, coding, sales, and more. In this post, we share the technical and philosophical lessons we’ve learned building a state-of-the-art research agent, and where we believe the field is headed.

Building for the Future

Agent Harness

The task of building an agent harness is to create a software layer that enhances a model’s runtime execution through context management, tool invocations, loop control, orchestration, and error handling. Building applications on top of rapidly improving models is, however, a modern engineering challenge. How can we design software today that absorbs the performance gains from future model releases?

This requires forecasting how models will evolve, staying optimistic about their progress, limiting assumptions, and avoiding hand-crafted optimizations.

We learned this the hard way seven months ago, when we had to abandon our first attempt at deep research and rebuild the entire system from scratch. The first architecture was complicated and sophisticated (we thought this was a good thing), but its assumptions became bottlenecks when the next generation of models arrived.