writing

32 posts

Jul 6, 2026

event-horizongraphqldataloaderdistributed-systemsarchitecture-decision-records

GraphQL Over Four Planes: An ADR That Contradicted Itself, and the N+1 We Measured Instead of Assumed

EventHorizon's dashboard has always been a live feed with no way to query history. Adding a read-only GraphQL layer over the Storage plane surfaced a self-contradicting ADR before a line of resolver code was written, and gave the DataLoader N+1 story an actual measurement instead of a "trust me, it's the reference implementation."

Jun 4, 2026

sentinel-l7architecturecomplianceidempotencyredis-streams

Closing the Loop: What We Actually Shipped from the Roadmap

Post #05 ended with a list of half-built features and a promise to ship them. This is the delivery receipt: compliance export, idempotency hardening, and the systems work that made them production-ready.

Jun 3, 2026

sentinel-l7idempotencyredis-streamspostgresqldistributed-systems

Triple-Defense Idempotency in a Crash-Prone Event Stream

At-least-once delivery guarantees every message is processed — not exactly once. This post traces the three idempotency layers in the Sentinel-L7 Axiom pipeline and the specific failure modes each one defends against.

Jun 2, 2026

sentinel-l7llmragcompliance-ai

Four Signals for Quality Scoring in LLM Pipelines

An LLM pipeline that produces no exceptions is not necessarily a pipeline that works. This post covers four signals for scoring the quality of compliance audit narratives produced by Sentinel-L7.

May 29, 2026

event-horizondistributed-systemskubernetesdockerdeployment

Closing the Gap: Persistent Tokens, Containers, and the Road to k3s

The previous post listed what EventHorizon needed before it could run in production. This one closes the list — persistent resume tokens, a multi-stage Dockerfile, a dependency-aware health check, and k3s manifests. Along the way, a silent data-loss bug that the test suite missed entirely.

May 26, 2026

sentinel-l7redis-streamsbackpressuredistributed-systems

Graduated Backpressure: Moving Beyond Binary Pauses

The first version of Sentinel-L7's producer guard was binary: above the threshold it stopped, below it ran full speed. This post covers why that fails under real load and what graduated backpressure looks like in practice.

May 19, 2026

sentinel-l7redis-streamsdistributed-systemsfault-tolerance

Self-Healing Worker Pools: Embedding XAUTOCLAIM in Every Worker

Sentinel-L7 runs two long-lived worker processes on Redis Streams. When a worker crashes mid-message, that message stays stuck in the PEL indefinitely. This post covers why the dedicated reclaimer daemon was replaced with embedded XAUTOCLAIM recovery in every worker.

May 11, 2026

musingsDIYdo-ocracy

The Catalyst of the Flawed First Move; or, The Freedom of the Sacrificial Draft

Why providing a deliberately flawed starting point is the fastest way to kill ambiguity and surface requirements.

May 5, 2026

event-horizondistributed-systemsretrospectivekubernetesobservability

What Comes Next: Multi-Server Deployments, Persistent Resume Tokens, and the Patterns That Transfer

EventHorizon is feature-complete as a learning vehicle. The interesting question is which of its patterns survive the move to a real production environment, and which need to be reworked entirely.

May 2, 2026

event-horizonclaudeaiworkflowadr

One AI, One Context File

I started this project with two AI assistants and a sync problem. I'm finishing it with one assistant and three documents that act as the project's durable memory. Here's what changed.

Apr 30, 2026

sentinel-l7architectureroadmapreflection

What Comes Next: Multi-Tenancy, Compliance Exports, and Closing the Loop to EventHorizon

A speculative look at what Sentinel L7 is pointing toward — the features that are half-built, the decisions still open, and what building this thing has actually taught me.

Apr 29, 2026

event-horizontestingfastifytypescriptrefactoring

Extracting the App Factory to Make Tests Stop Lying

Importing a server module should not bind a port. It should not connect to MongoDB. It should not start a metrics interval. Once your tests can't import your server without ten unrelated things happening, you've already broken your own contract.

Apr 28, 2026

event-horizonzodtypescriptvalidation

Zod Won. Here's What It Cost.

I evaluated Valibot. I picked Zod. I lost half a day to a UUID validator that was technically more correct than the previous version. Here is what I'd tell my past self about validation libraries.

Apr 19, 2026

testingjestvitesttesting-librarynextjsnestjsRhizoBook

Tests, Rough Edges, and What's Still Ahead for RhizoBook

The backend Jest strategy, frontend Vitest setup, two bugs found while writing tests, and an honest account of what the app still can't do.

Apr 10, 2026

event-horizonmongodbchange-streamsdistributed-systemsdebugging

Resume Tokens and the Lie of 'Just Reconnect'

The dashboard said everything was fine. Stats updated. Connection dot was green. Nineteen thousand events had moved through the pipeline and the live feed was a frozen screenshot.

Apr 5, 2026

event-horizontestingvitestmongodbdistributed-systems

Testing What You Can, Naming What You Can't

There are parts of this system I have no automated tests for, and that is a deliberate design decision. The trick is being honest about which parts those are and why.

Apr 3, 2026

event-horizonrabbitmqdistributed-systemsperformance

Backpressure Is Just a Number You Have To Pick

AMQP prefetch is one integer in one config file. It is also the difference between competing consumers and one worker eating the entire queue while the others sit idle.

Apr 2, 2026

sentinel-l7redisllmarchitecturedebugging

Draining 657 Messages and Running Out of AI on the Way Down

Integrating a Python anomaly sidecar, hitting Gemini quota limits within minutes, and why a pluggable driver abstraction is not over-engineering.

Apr 2, 2026

event-horizondistributed-systemsmongodbrabbitmq

At-Least-Once Is a Lie Without an Idempotent Receiver

How I almost shipped duplicate documents into MongoDB, and why I now think of unique indexes as load-bearing infrastructure rather than schema decoration.

Apr 1, 2026

sentinel-l7ragvector-dbllmcompliance

RAG Is Easy. Getting It to Actually Retrieve Anything Is Hard.

On building a policy knowledge base for compliance analysis — and the silent failure that made it look like everything was working when nothing was.

Apr 1, 2026

event-horizonrabbitmqdistributed-systemserror-handling

Three Strikes and the Dead Letter

Why the worker republishes failed messages instead of nacking them with requeue=true, and how a single boolean flag is the difference between a healthy pipeline and a frozen one.

Mar 31, 2026

event-horizondistributed-systemsgraceful-shutdownfastifyrabbitmqmongodb

The Seven-Step Shutdown

There are exactly seven steps in EventHorizon's graceful shutdown, in exactly one order, and every reordering loses data in a specific way.

Mar 30, 2026

event-horizondistributed-systemsarchitecturetypescript

Four Planes, One Direction: The Shape of EventHorizon

Why I named the four stages of the pipeline before I wrote any code, what naming bought me, and what backflow between them would have cost.

Mar 29, 2026

nestjsprismabusiness-logicappointmentsbackendRhizoBook

The Hard Part: Appointment Scheduling, Conflict Detection, and Role-Aware Queries

How conflict detection, a status state machine, and a single role-aware endpoint handle the core scheduling logic in RhizoBook.

Mar 8, 2026

prismasecuritynestjsapi-designbackendRhizoBook

What Strangers Shouldn't See: Securing the Public Provider API

How Prisma's include silently exposed sensitive fields on a public endpoint, and how explicit select fixed it at the query level.

Feb 27, 2026

sentinel-l7vector-dbembeddingscaching

Semantic Caching, or: Why I Spent Three Days Making a Cache Hit Work

Fingerprints, embeddings, and the exact-timestamp bug that gave me a 0% cache hit rate until I stopped being clever and started being dumb.

Feb 22, 2026

nextjsnextauthapp-routertypescriptfrontendRhizoBook

Wiring Up the Frontend: Next.js App Router, NextAuth, and a Rewrite Proxy That Saved Me

How I structured the Next.js frontend with two route groups, wired up NextAuth JWT sessions, and replaced a fragile build-time env var with a server-side rewrite proxy.

Feb 19, 2026

sentinel-l7laravelredisarchitecture