LlamaIndex has released a new approach to easily create agents called Workflows, which use an event-based architecture instead of traditional pipelines or chains. This new approach brings new considerations for developers and questions on how to evaluate and improve these systems. Workflows are an orchestration approach that lets you define agents as a series of Steps, each representing a component of your application. This event-driven architecture gives more freedom to applications to jump around and allows steps to be self-contained, making it easier to handle intricate flows and dynamic applications. Workflows are great at handling complicated agents, especially those that loop back to previous steps, but may add unnecessary complexity to linear applications. To visualize the paths taken by your Workflows, you can use Arize Phoenix, which provides an integration with LlamaIndex that allows you to easily visualize step-by-step invocations without adding extensive logging code. Workflows can also be evaluated using a similar approach as evaluating any agent, breaking down the process into tracing visibility, creating test cases, breaking components into discrete parts, defining evaluation criteria, running test cases, and iterating on your app.