Stellan Lee

Case Notes

Anonymized failure-pattern notes. These are not company stories; they are examples of how the fault boundary moved before the real cause was found.

Agent failure was not a Git change

An agent workflow stopped working, but recent repository changes did not explain the failure.

Agent Runtime · Toolchain · Version Compatibility

Looked like
Code regression
Actually
Outdated toolchain version
Layer
Agent runtime / Toolchain

Evidence trail

Recent code changes did not line up with the failure
Runtime behavior differed from the expected workflow behavior

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Database startup failure was not database configuration

A customer-site MySQL service failed to start, and normal database-level checks did not explain the issue.

Linux · MySQL · Shared Libraries · Field Debugging

Looked like
MySQL configuration issue
Actually
Replaced shared library
Layer
Linux runtime dependencies

Evidence trail

Database-level checks did not explain startup failure
The service failed before meaningful MySQL behavior appeared

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Intermittent connectivity was not tunnel instability

An edge device appeared unstable through remote access tooling, but the actual failure was inside the local network.

Edge · Networking · IP Conflict · Customer Site

Looked like
VPN / tunnel instability
Actually
LAN IP conflict
Layer
Network / Customer site

Evidence trail

Connectivity was intermittent, not consistently broken
Remote access appeared unstable, but local identity was suspicious

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