The engineering problem
An incident investigation often begins with incomplete information spread across several places. Finding a signal is one task; working out which service, environment, and period it describes is another. Engineers need that context before a useful recovery discussion can happen.
I built an internal investigation tool for my team to bring operational evidence into a more coherent workflow. The purpose was practical: make it easier to investigate a production problem without repeatedly reconstructing the surrounding context by hand.
My contribution
I designed and built the tool around the investigation process. It brings together operational signals and infrastructure context so the team can examine a problem across layers. It has been used by my team during production investigations.
Architectural reasoning
The core problem is correlation. Logs, monitoring information, and telemetry can describe different aspects of the same event. Infrastructure context helps make their relationship intelligible.
The conceptual diagram separates evidence, correlation, investigation, and engineer judgment. It explains the problem the tool addresses without reproducing the internal deployment.
A useful investigation also needs a distinction between an observation and an explanation. Evidence can support a hypothesis without proving it. That distinction matters when a team is making operational decisions under time pressure.
Decisions and constraints
I approached this as engineering support for an existing team workflow. The value is in connecting relevant information and helping an engineer decide what to inspect next.
I think about correlation in terms of time, source identity, and uncertainty. These are design principles I use to reason about the workflow.
Time windows. A narrow window can hide the build-up to a failure; a broad one can bury a useful signal in unrelated events. Comparing timestamps is only useful when I understand the period each observation covers and whether the context is still current.
Source identity. Bringing evidence together should help an engineer find the original observation. A combined view is less useful if it hides where a statement came from or makes an interpretation look like a source fact.
Uncertainty. An absent signal can mean healthy behavior, missing data, or an unavailable source. Two observations close together in time can support a hypothesis without establishing a shared cause.
Investigation workflow. I want tooling to help an engineer form a question, inspect the evidence, and revise an explanation. The tool is also a dependency: a useful operating approach should leave engineers able to investigate when the combined view is unavailable.
Outcome and lessons
The result is an investigation tool used by my team to bring signals and system context into the same workflow.
The lesson I take from this work is that the surrounding context is part of the evidence. A collection of signals becomes more useful when an engineer can relate them to the system being investigated and keep the explanation open to revision.