RFO.Reason for Outage
by Christy Steyn
Christy Steyn, architect of an enterprise agentic RAG platform
Christy SteynEnterprise architect. Post-mortem failure analysis for real production systems.

Post-mortem analysis for AI architects

Reason forOutage.

Real failures.
Full traces.
Architecture decisions.

Post-mortems for agentic AI systems, written by the architect who built one. I run an enterprise agentic RAG platform for a global enterprise. When it breaks, I trace what happened, find the cause, and write up the fix. You get the lesson without the outage.

Read the post-mortems ↗
RFO / Anatomy of an agentic system

The model is one part.

Evidence, tool use, and the boundaries around action. Every post-mortem starts with the traces.

Illustrative workflow: sources supply retrieved context to an agent. A task and constraints guide the agent. Read-only tools return observations to context. An answer cites evidence; a consequential action requires approval.
Conceptual architectureRead-only tool results feed back into context. Consequential actions require approval.
The format

One real failure,
followed all the way down.

Each post-mortem takes a single production incident through the whole agentic RAG stack, dead ends included. If I cannot reconstruct what the system did from its traces, I cannot explain the failure, so the first fix is often better observability. Technical enough to reuse, plain enough to forward to your manager.

  1. 01 / Symptom

    What did they see?

    What the user or operator saw, in their words.

  2. 02 / Timeline

    What did the system do?

    Reconstructed from the traces.

  3. 03 / Root cause

    Where did it break?

    Ingestion, chunking, retrieval, reranking, generation or tool use.

  4. 04 / Blind spot

    Why was it missed?

    Why monitoring missed it and what I measure now.

  5. 05 / Fix

    What changed?

    What I changed, what I rejected, and how I proved it worked.

  6. 06 / Decision

    What should you decide?

    The architecture choice, so you can make your own.

Latest post-mortems
Written by the person who built it

Architect and builder,
not a case study.

I designed and built an agentic RAG orchestration layer for a global enterprise, and I wrote the code. The platform is fully traced, with golden evals behind every change.

I came up through network engineering, so I care most about what happens after deployment.

01 / Architecture

Retrieval, ingestion, agents.

The design decisions and the boundaries between components.

02 / Failure analysis

Follow the failure.

What broke, what the traces showed, and what reduced the risk.

03 / Observability

Know what it did.

Tracing, golden evals, and review gates around AI systems.