$ cat post/man-page-at-two-am-/-the-deploy-left-no-breadcrumbs-/-i-wrote-the-postmortem.md
man page at two AM / the deploy left no breadcrumbs / I wrote the postmortem
Title: On Edge: Debugging an AI Copilot in Production
August 25, 2025. Another day, another layer of AI-native tooling integrated into our stack. As platform engineers, we’ve been on a journey to make development as seamless as possible, with copilots and agents assisting us at every turn. But the real fun begins when they start making decisions that aren’t quite as clear-cut.
Today, I found myself face-to-face with one such decision. It started innocently enough; our AI copilot was supposed to help me optimize some edge compute workloads using eBPF (extended Berkeley Packet Filter) for better performance and lower latency. But somewhere between the promise of seamless optimization and reality, something went awry.
The Setup
We’ve been running an eBPF-based system that offloads certain network processing tasks from our application servers to specialized network devices. This has helped reduce load on our CPUs and improved overall throughput. Our AI copilot was supposed to automate this setup by suggesting the best configurations for each device based on real-time metrics.
The Problem
On one of our edge nodes, something wasn’t right. The system had flagged a critical issue: an unexpected spike in packet loss. Normally, I would have reached for my trusty tcpdump and started sniffing, but with the AI copilot assisting, that felt like a step back.
The copilot’s dashboard showed everything was nominal. No unusual traffic patterns, no signs of network congestion, nothing out of the ordinary. But the packet loss persisted. I decided to dig deeper into the eBPF programs running on the device in question.
I fired up bpftrace and started tracing the relevant sections of code. As I inspected each function, one line stood out: a call to bpf_perf_event_read. This function is used to read performance events, like interrupts or cache misses. The trace showed that this function was being called more frequently than expected.
Debugging
I hypothesized that perhaps the copilot’s optimization had altered how these events were being captured, possibly leading to a race condition in our eBPF programs. To test this theory, I rolled back the most recent changes and re-ran the tests. This time, everything behaved as expected.
But here’s where things got interesting: when I tried to implement a workaround that would handle the increased load on bpf_perf_event_read, the copilot flagged it as “inefficient” and suggested a different approach. This time, it proposed using an alternative event-based mechanism to track performance metrics.
The Argument
This is where the real fun began. I argued that the current implementation was not only stable but also provided more granular control over our network processing tasks. The copilot’s suggestion, while clever in its own right, introduced a new level of complexity without clear benefits. We were entering the realm of AI making decisions based on what it thought was “optimal” rather than what we knew worked.
After some back-and-forth, I decided to split the difference and implement both approaches side by side. This way, we could gather more data and make an informed decision later. For now, the original eBPF programs would stay in place, with the copilot’s suggestions as a fallback option if they proved to be better.
Lessons Learned
This experience taught me that while AI copilots are incredibly powerful tools for automation and optimization, they should never replace human judgment entirely. There’s still a lot of nuance and context that a machine learning model can’t always capture or understand without proper oversight.
As I hit save on the new code changes, I couldn’t help but think about how far we’ve come since the early days of Kubernetes when everything seemed so exciting yet so raw. Now, with AI-native tooling everywhere, it’s easy to lose sight of what really matters: ensuring that our systems are reliable and performant.
Conclusion
In the end, the copilot was right—sometimes. But for today, at least, I’m sticking with my old-fashioned debugging techniques. After all, there’s something comforting about knowing exactly why your system is behaving the way it is. And maybe, just maybe, that’s what makes us better engineers: the ability to understand and trust our own judgment.