Teemu Piirainen

Notes from building
with AI in practice.

Production AI systems, agentic software development and what the work feels like while it changes.

A Claude Code v2.1.285 terminal running Opus 5.5, with /claude-api prompt-audit typed at the prompt and auto mode on.

Oct 15, 2026 · ai · claude · agents · workflow

How to Audit Your Claude Code Instructions After a Model Upgrade

After moving to Opus 5.5, my Claude Code instructions went 22k → 13k tokens. Run the prompt audit, review with Claude, then test what you removed.

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Two cards side by side. CLAUDE.md holds "Follow the existing architecture" and "Keep the solution simple", labelled Judgment. .claude/settings.json holds an ask rule for Bash(git push *) and a SubagentStop hook running check-tests.sh, labelled Enforced.

Oct 11, 2026 · ai · claude · agents · workflow

Claude Code Permissions and Hooks: Rules Your Prompt Can't Enforce

"Never push without asking" belongs in settings.json, not only in the prompt. How to set up Claude Code permissions and hooks, with real examples.

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AI code review: a git diff in a terminal window, labelled one code change, with arrows to three runs of the same AI review agent. Each run finds some of the earlier runs' issues and some new ones; the third run's new finding is marked 'New valid issue. Run 3.' Title: Same code. Same agent. Different findings.

Oct 6, 2026 · ai · code-review · agents · workflow

AI Code Review Is Statistical: Why One Run Is Not Enough

Run an AI code review twice on unchanged code and the findings can differ. How I'd design for it: repeated runs, fresh context, tracking what each adds.

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A SKILL.md workflow graph: Start, Architect and Developer, then security and bug validators in parallel into a Pass? decision. No loops back to Developer; Yes goes to your review, which approves a commit or requests changes from Developer.

Oct 3, 2026 · ai · claude · agents · workflow

Graph Engineering for Coding Agents: A Simple First Workflow

Graph engineering for coding agents sounds complicated. A simple first workflow in Claude Code: draw it, write three agents and one SKILL.md.

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A network diagram: a teal agent marketplace hub connected to eighteen developer nodes. Nine orange nodes on solid lines are marked 'uses it on real work', nine white nodes on dashed lines 'has it installed'. Caption: every line exists, not every line is live.

Sep 30, 2026 · ai · agents · adoption · workflow

An Agent Marketplace Solves Distribution, Not Adoption

A marketplace ships agents and skills to every developer. It does not make anyone use them. Six questions I'd ask once the technical part works.

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A Claude Code terminal with /plugin install aw-review@awave-agents typed at the prompt, with arrows fanning out from it to the Codex, GitHub Copilot and OpenCode logos.

Sep 27, 2026 · ai · agents · claude · codex · workflow

One Source, Multiple Harnesses: Building a Portable Agent Marketplace

I run the same agents in Claude Code, Copilot CLI and Codex from one source. How the build adapts packages, hooks and roles, and what broke on the way.

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A Claude Code terminal window listing the aw-review plugin from the awave-agents marketplace, with /plugin install aw-review@awave-agents typed at the prompt.

Sep 17, 2026 · ai · claude · agents · workflow

How to Build a Personal Agent Marketplace for Claude Code

40+ agents and skills, five plugins in every project. How I package them as a Claude Code plugin marketplace, with my aw-review reviewer as the example.

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Four stage cards from generic AI to AI-enabled services, darkening from grey to accent, with an AI autonomy strip above and a business impact strip below ending in new revenue.

Sep 9, 2026 · ai · strategy · legal · adoption

What a software factory taught me about AI strategy for law firms

I lived it in software: AI agents do the work and the advantage moves into the harness around the model. Now it is legal work. Nine AI strategy decisions.

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Part of the AI software factory diagram: the task-level developer and validator loop, its PASS and FAIL branches, and the artifact rail beside them.

Aug 12, 2026 · ai · code-review · codequality · programming · softwareengineering

If AI Writes and Reviews the Code, What Is the Human Approving?

AI agents write the code and independent AI code review gates it on evidence. What a PASS establishes about AI-generated code, and what a human approves.

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A before-and-after illustration of the same specialist at a desk: on the left, buried under a tall stack of documents and binders with a clock reading four hours; on the right, one checked document with a clock reading minutes.

Jul 23, 2026 · ai · adoption · finance · risk-management · compliance

What Oma Säästöpankki measured after four weeks of AI coaching

A four-week AI Coaching Program at Oma Säästöpankki. The pilot lead reported 15–50% time savings; one regulatory task went from four hours to minutes.

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Illustration of one runner still sprinting alone down a track while a group of runners who have already finished waits at the line.

Jul 22, 2026 · ai · agents · workflow

AI Optimized My Throughput. It Did Not Optimize Me.

My AI agents raised my output more than 10x, and my workdays got heavier, not lighter. AI brain fry, decision fatigue, and becoming the bottleneck.

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Illustration of a developer at a 'Decide what's next' console over an intake-to-review pipeline, as hand-coding and manual review fade away.

Jul 7, 2026 · ai · learning

AI took my job. Twice in one year. I still have one.

What a year of coding with AI did to my work, my role, and me. AI took over the writing, then the checking, and I had to relearn my role three times.

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Commit-history chart of five months of Claude Code contributions, the agent's 711 commits dwarfing my 98.

Jun 30, 2026 · ai · claude · architecture

5 months. 100% Claude Code. Zero architectural drift.

Every line of code in a five-month web service project was written by Claude Code. Here is the system that kept the architecture from drifting.

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An AI-generated decision summary for a Stripe subscription build: 18 decisions grouped into Foundations, Product model and other areas for a human to review.

Jun 2, 2026 · ai · agents · claude

AI Has Made Me a Text Parser. And I'm Terrible at That.

Claude writes a ten-page spec in a minute. Reading it takes me two hours. The fix was giving the human a ViewModel instead of a database dump.

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The words FOMO, FOMAT and FOMUT stacked with downward arrows on a dark background.

May 11, 2026 · ai · agents · workflow

FOMO, FOMAT, FOMUT, and the Bottleneck That Turned Out to Be Me

A year ago the AI agents were the bottleneck in my workflow. Now they run for hours unattended, and the bottleneck is me. Why that is a better problem.

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A 'Quality Pipeline for AI-Written Code' flowchart from feature request through human requirements, agent implementation and an independent validator that must pass before commit.

Mar 16, 2026 · ai · testing · agents · security

How I Validate Quality When AI Agents Write My Code

The eight-gate quality pipeline of tests, validator agents, reviews and deploy verification that turns AI-generated code into evidence.

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Mar 1, 2026 · ai · agents

I'm not working with a tool anymore

Eija Moisala asked me one question for her Ask a friend series: what have you been experimenting with, and what did it teach you?

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Feb 7, 2026 · ai · agents · performance

Your AI Coding Agents Are Slow Because Your Tools Talk Too Much

A validator agent spent 6-9x longer reading test results than the tests took to run. The fix was not a better prompt. It was quieter tools.

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Teemu Piirainen outside the Nokia Oulu 'Home of Radio' building.

Nov 20, 2025 · training · teams

Four training sessions with the Nokia team in Oulu

Back in Oulu with the same Nokia team: four sessions across half a year, and the one question that shows whether training actually stuck.

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Teemu Piirainen presenting to a seated audience at Elisa, beside a slide reading 'Just whistle while you work' with the seven dwarfs.

Nov 3, 2025 · ai · training · adoption

Turning AI into real results: what Elisa got right

What Elisa and a team led by Eija Moisala got right about AI adoption: leadership, permission, and making learning part of everyday work, with results in weeks.

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Teemu Piirainen speaking at a lectern at Ilmarinen, beside a slide comparing manual and AI-assisted delivery times across task types, about 3x faster overall.

Oct 20, 2025 · ai · training · adoption

Bringing AI to everyday work: speaking at Ilmarinen

A recap of my talk at Ilmarinen on making AI a real teammate at work: moving past pilots, into everyday workflows, and a culture that keeps learning.

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Teemu Piirainen speaking about AI adoption at the North Karelia Chamber of Commerce Digiklinikka event, beside a slide reading 'An AI is only as good as the prompt and context you give it.'

Oct 7, 2025 · ai · training · adoption

AI training for employees: how to guide AI from pilot to practice

My Digiklinikka talk for the North Karelia Chamber of Commerce: why AI has to be guided, and how teams move it from small pilots to everyday practice.

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