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Skill-Evolution Retrospective

Fri, 03 Apr 2026 00:00:00 +0000

We Built an AI-Powered Prompt Optimizer and It Taught Us We Were Solving the Wrong Problem

We built a system to rigorously test whether our AI instructions actually worked. Halfway through, we discovered our test environment had been handing the model its own answer key.

The Idea

Claude Code lets you package instructions into skills — persistent system prompts for specific domains, packaged as markdown files. A skill for code review. A skill for infrastructure decisions. A skill for knowing when to stop and ask a question instead of charging ahead.

Taking the Pager is Taking the Wheel, Not the Title

Sat, 16 Dec 2023 00:00:00 +0000

This post was partly inspired by Sean Kilgore’s recent blog about Common Errors in the Paved Path metaphor. Sean’s language mirrors a metaphor that surfaced within my team about our On-Call Rotation. Sean contrasts the “paved path” an organization provides to its developers with the “vehicles” each team puts on that path. My team talks about being on-call in terms of “taking the wheel of the vehicle,” instead of the more common “being responsible for fixing anything that goes wrong.”

Teaching Crossplane to Play Poker

Thu, 10 Mar 2022 00:00:00 +0000

Let’s Teach Crossplane to Play Poker

The Penguin Book of Card Games lists over 250 games which can be played with a standard deck of playing cards. Most of those games don’t require any changes to the deck. Blackjack, poker, gin, go fish, crazy eights, old maid… these games all use the same 4 suits of 13 ranks.

When we start composing infrastructure with Crossplane, it’s a lot like learning a new game with playing cards. We know the pieces. We know what they do. What we need to learn is how we’re going to arrange them to play a new game.

Conformance Testing Crossplane Configuration Packages with Sonobuoy

Fri, 28 Jan 2022 00:00:00 +0000

Conformance Tests for Crossplane Configuration Packages

When crossplane graduated to Incubation status we published a conformance for crossplane and its providers. I started to wonder if we could use the same tools and framework for testing Configuration Packages, as well as Provider Packages.

A unified testing strategy for all crossplane packages could simplify our build and test pipelines. And it would provide a method for testing and validating external packages. Especially if we adopted a tool and framework which were already community standards.

TDD For Crossplane Packages with Skaffold

Fri, 14 Jan 2022 00:00:00 +0000

Crossplane Package Development

Crossplane Packages, and specifically the Composition Engine, allow Platform Teams to publish Composite Resources for use by Development Teams or Platform Operators. The end result of a Crossplane Composition is always going to be a set of valid YAML documents which define Crossplane Managed Resources.

Because the output of our compositions is this declarative set of YAML documents, we have the ability to write tests for our configurations. And once we can write tests, we can do test-driven development.

Testing Crossplane Packages with Kuttl

Fri, 07 Jan 2022 00:00:00 +0000

Crossplane Package Test Loop

The test loop for Crossplane Packages is always going to be an end-2-end test in a working kubernetes cluster. In order to validate that a package behaves as desired, we must:

Access a Kubernetes Cluster
Install Crossplane and required providers on that cluster
Configure our Composite Resources (XRs) on that cluster
Submit a Composite Resource or Claim
Validate that we got the desired Resources in response
Repeat the last 3 steps for each Resource

Kuttl

kuttl (The KUbernetes Test TooL) is a toolkit for writing tests against Kubernetes. Using kuttl, engineers can apply manifests, helm charts, or run kubectl commands against a kubernetes cluster, then compare the cluster state against a yaml file to validate the result.

About Me

Mon, 01 Jan 0001 00:00:00 +0000

Writer

Do I write science fiction? I wear a watch that Dick Tracy never dreamed of and I’m typing this on a device that would look at home on Captain Picard’s desk. I write fiction about people trying to make sense of a world that runs on science.

Engineer

I’m a kubernetes fan boy and I will talk about it at parties if not monitored.

I’ve worked with a lot of great people on projects like Call of Duty: Elite, Society6, Procore, and Upbound, the company behind the open source Crossplane project.