Topic archive

Engineering

8 published stories filed under Engineering.

Pen-and-ink sketch of a small clockwork robot working at a tool-covered workbench late at night while a human sleeps peacefully on a couch in the background, a wall clock reading 2:00 above

ai April 24, 2026 13 min read

The Agent Stays Up Late, Not Me

Every senior engineer knows the right way to set up a codebase. None of them do it. Here’s the four-stage framework we use — The Ratchet — to take a vibe-coded project all the way to a thing you’d trust in production, and the punchline about why this only just became worth doing.

Most teams have always known they should be running tests, type-checking, security audits, accessibility checks, dead-code analysis, prose linting, and a coverage floor. Most teams run two of those. Here’s why that math has finally inverted, and the four-stage framework we use to ratchet a vibe-coded project to a hardened one.

Keith Pattison

Founder, Black Flag Design

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Pen-and-ink sketch of two keys on a ring with paper labels AI STUDIO and VERTEX, a thin red arrow pointing at the VERTEX key

ai April 24, 2026 4 min read

Two Kinds of Google Keys, Two Endpoints

The Gemini key that rejects your request with 403 API_KEY_SERVICE_BLOCKED is almost certainly a Vertex key being sent to the AI Studio endpoint. Here is how to tell them apart, and which endpoint to use.

We spent an hour chasing what looked like a billing issue and turned out to be a key-format mismatch. The key worked. Google was just telling us we had pointed it at the wrong building. If you are shipping a Gemini integration, this is the one-page reference we wish we had read first.

Keith Pattison

Founder, Black Flag Design

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Pen-and-ink sketch of three parallel doorways with figures, one doorway has a question mark above it, a red START arrow points toward the middle

claude code April 24, 2026 2 min read

Context Laundering

The one use case where spawning a sub-agent always pays off. It is not parallelism. It is triage for your main context window.

We use the word parallelism when we talk about sub-agents. Most of the time we are not actually running in parallel. We are protecting the main context from heavy reading. That is the move.

Eli Wood

CEO, Black Flag Design

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Terminal-output panel showing two red FAIL lines and a green PASS line, with an arrow pointing from red to green

ai April 24, 2026 6 min read

Red/Green TDD When Your Dep Is a Generative API

How to test-drive code that integrates with Gemini, Claude, or any non-deterministic API — without pretending the API is deterministic.

Gemini does not care about your unit tests. But your unit tests can still be green, fast, and trustworthy — if you put the seam between your code and Gemini in the right place. Here is the pattern we used to ship a CMS image-generation feature in under a day, with every layer TDD'd and the Gemini boundary mocked without hand-waving.

Keith Pattison

Founder, Black Flag Design

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Whiteboard sketch: one task branching into five arrows that tangle into a knot, with a small caution mark at the center.

claude code April 23, 2026 6 min read

The Sub-Agent Skill Trap

Spawning a sub-agent looks like the obvious move for any multi-step task. Half the time it is the wrong one, and the signals are quieter than you think.

Sub-agents feel like leverage: one call, many workers, results in parallel. But most of the time we reach for one, the work was never parallel to begin with. Here is how to spot the trap before you fall in.

Eli Wood

CEO, Black Flag Design

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Black Flag Journal

claude code April 20, 2026 5 min read

What a Year of Claude Code Trails Tells You About Your Team

Claude Code leaves evidence — sessions, commits, PRs, review notes. Read it like a logbook and you'll find what devs actually need to know before they go deeper.

After a year of shipping with Claude Code across real client work, the signal isn't in any single session — it's in the trails. Here's what those trails told us about where Claude Code shines, where it drifts, and the habits devs should build before they lean in harder.

Eli Wood

CEO, Black Flag Design

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Black Flag Journal

ai April 20, 2026 5 min read

Six Principles for Shipping Reliable Software with AI

How we stay sane while "vibes" infiltrate codebases — the playbook we run on every engagement.

AI-generated code floods projects with promises of speed and delivers drift instead. Six disciplines turn it back into a reliable tool: small scope, human judgment, repeated purpose, weekly planning, active management, and continuous improvement.

Keith Pattison

Founder, Black Flag Design

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Black Flag Journal

playbook April 20, 2026 6 min read

The Black Flag Playbook: Six Principles for Shipping with AI

Battle-tested principles for teams building real software with AI-generated code. Human judgment, tight scope, and weekly evidence — the disciplines that keep AI-built systems reliable.

The six rules we use to ship production software with AI. Small scope, weekly demos, human-led oversight, and continuous improvement — drawn from six months of real client engagements.

Keith Pattison

Founder, Black Flag Design

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