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a diff I once wrote / the service mesh confused us all / the service persists


Debugging Myths vs. Reality in a LLM-Oriented World

February 12, 2024

This week has been filled with AI chatter and LLMs everywhere you look. The Sora video creation tool got a lot of buzz, and Netlify’s $104k bill for a simple static site? Pricey indeed. But let’s get real here—when I’ve dug into the depths of our infrastructure to tame wild LLM-generated code, that’s where the true grit lies.

The Setup

We’re dealing with an AI-driven platform where we generate massive amounts of code using large language models (LLMs). It’s a thrilling time, but it comes with its own set of challenges. One of those is debugging—specifically, debugging generated code. Let me break down the reality vs. myth of this process.

Debugging Myths and Reality

Myth: AI-Generated Code is Perfect

Reality Check: AI-generated code isn’t perfect by a long shot. Take that Netlify bill as an example—it’s easy to think LLMs are infallible when they spit out a few lines of Python or JavaScript, but once the complexity ramps up, it’s clear they’re not flawless. Recently, we had a case where the model generated some server-side logic that was supposed to handle file uploads.

The issue? The code didn’t properly validate the file size before saving it to disk. We found this by running unit tests and noticing failures. A quick fix, but it highlights how even something as straightforward as validating a simple upload can go wrong when relying on AI.

Myth: LLMs Understand All Edge Cases

Reality Check: LLMs do an excellent job with common scenarios, but edge cases? Not so much. Remember that self-balancing cube I read about in Hacker News? That’s fun, but not exactly what we need right now. We had a case where the model was asked to handle a scenario involving file uploads and user authentication simultaneously. The response was coherent, but it completely ignored a critical edge case: concurrent access issues.

When two users tried to upload files at the same time, one’s session got overwritten by another’s data. Oops! This is where understanding the underlying constraints of your application becomes crucial. LLMs excel in generating basic logic, but they need human oversight for edge cases and complex interactions.

The Role of Platform Engineering

In our platform engineering team, we’re navigating this landscape with tools like CNCF projects (specifically Helm and Kubernetes) to manage our infrastructure. WebAssembly on the server side is also an interesting area to explore, although it’s still early days for adoption in cloud-native environments. We’ve been experimenting with using WebAssembly modules within our containerized microservices—just for fun, you know?

But back to debugging. With FinOps and cloud cost pressure tightening the belt, every second spent on fixing a bug is precious. DORA metrics have become part of our regular workflow, tracking deployment frequency and lead time for changes. We’re constantly pushing ourselves to be more efficient.

Learning from the Process

Debugging AI-generated code has taught us valuable lessons:

  1. Validation: Always validate the output with unit tests.
  2. Edge Cases: Don’t assume LLMs cover all edge cases. Manual review is necessary.
  3. Human Oversight: While LLMs are amazing, they’re still a tool and need human expertise.

Next Steps

For next steps, we’re looking at integrating more robust validation mechanisms into our code generation pipeline. Maybe even adding a step for manual review before deploying generated code to production. This isn’t just about saving costs; it’s about ensuring the quality and reliability of our applications.

In the end, while AI is fantastic, it’s not a replacement for human expertise. Debugging AI-generated code has been a real eye-opener—full of both challenges and learning opportunities. Stay tuned as we continue to navigate this exciting but complex landscape!


That’s where I’m at right now. What are your thoughts on debugging AI-generated code? Share in the comments below!