AI Agents Failures & How To Stop Them

Danilo Campagna from Posthog discusses common LLM code generation failures and strategies for improvement, focusing on context, architecture, and human error.

Speaker Danilo Campagna presenting on LLM code generation failures to an audience.
Image credit: AI Engineer Europe· AI Engineer

In a recent presentation at AI Engineer Europe, Danilo Campagna, an engineer at Posthog, shared critical insights into the common failures of Large Language Model (LLM) code generation agents and offered strategies to overcome them. Campagna, who works on the Posthog Wizard, a tool that uses AI to analyze and integrate Posthog into projects, highlighted that while LLM agents can offer immense productivity gains, their inherent limitations require careful management.

AI Agents Failures & How To Stop Them - AI Engineer
AI Agents Failures & How To Stop Them — from AI Engineer

Danilo Campagna's Expertise

Danilo Campagna's role at Posthog positions him at the forefront of integrating AI capabilities into developer tools. His work on the Posthog Wizard involves understanding how LLMs can assist in complex tasks like project analysis and integration, which often require a deep understanding of code and frameworks. His perspective is grounded in practical application, focusing on the real-world challenges and solutions encountered when deploying AI agents.

LLM Code Generation Failures: The Core Issues

Campagna began by addressing the fundamental failures he has observed in LLM code generation agents. He noted that a significant issue is what he terms "model rot," which occurs when the model's understanding of the world, or in this case, the codebase, becomes outdated. This can lead to agents producing code that is syntactically correct but functionally flawed or incompatible with current project dependencies.

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He elaborated on this by stating, "Training a model takes a lot of time. It's not the time, it's the money." This highlights the significant investment required to develop and maintain these models. The trade-off, as Campagna explained, is that models that are not continuously updated or retrained can become less effective over time, producing outputs that are no longer representative of the current state of the world or the project.

Strategies to Mitigate Failures

To combat these failures, Campagna proposed several key strategies. One primary approach is to provide the AI agents with a clear and well-defined context. He explained that rather than expecting an agent to "figure it out," providing specific instructions and relevant data significantly improves the accuracy and utility of the generated code.

Campagna stated, "We start off by even telling the agent upfront exactly what we're going to do. We don't tell them, 'Hey, go figure out what we're going to do.' We tell them, 'We're going to integrate Posthog here.'" This direct approach ensures the agent is focused on the task at hand and has the necessary information to succeed.

Another critical strategy is to implement what he calls "model airplanes." This refers to creating structured data that represents the desired output or behavior. By providing these structured examples, the agent can learn to replicate the intended functionality more reliably. He elaborated, "What we do is we start off by even telling the agent upfront exactly what we're going to do. We don't tell them, 'Hey, go figure out what we're going to do.' We tell them, 'We're going to integrate Posthog here.'"

The Role of Human Error and Overengineering

Campagna also touched upon the inherent challenges of human error and overengineering in the context of AI agent development. He noted that while AI agents are designed to automate tasks, the human element in defining their goals and the underlying architecture remains crucial. Overengineering, or building overly complex systems, can introduce unforeseen issues and make it harder for agents to perform their tasks effectively.

He warned, "The big threat to our agent outcomes is ourselves. We're flawed, we're fallible beings." This sentiment underscores the need for careful oversight and validation of AI agent outputs. Even with advanced AI, human judgment and intervention are essential to ensure the reliability and correctness of the final product.

Furthermore, Campagna highlighted the issue of "bad architecture" and how it can lead to agents producing incorrect or nonsensical outputs. He explained that when an agent is forced to operate within a poorly designed system, its ability to perform its intended function is compromised. "The models don't know what the hell is going on anymore. They're making up keys, they are inventing APIs that don't exist," he stated, illustrating the potential for agents to generate plausible-sounding but ultimately incorrect information when faced with architectural limitations.

The Importance of Iteration and Feedback

The process of developing effective AI agents, Campagna emphasized, is an iterative one. By continuously monitoring the agents' performance, gathering feedback, and making adjustments to their inputs and underlying architecture, developers can improve their reliability and accuracy over time. This feedback loop is critical for identifying and rectifying issues before they impact the end-user.

He concluded by stressing the importance of asking the right questions during the development process: "What can we do better? How can we set ourselves up for success?" The key, he suggested, lies in providing clear, structured information and continuously refining the models based on their performance in real-world applications.

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