Berlin / riethmayer.com

10% strategy, 20% culture, 70% execution. A better version shipped today beats a perfect one later.

Jan Riethmayer

Product-minded agentic engineering for AI-native systems that survive production.

I build systems measured by outcomes: faster decisions, less busywork, behavior that actually changes. Agents, evals, and quality gates are the means, not the point.

Execution / 70%
Culture / 20%
Strategy / 10%
Urgency / Now
01 / Operating mode

Urgency is a strength. Iteration is the method.

Interested in every facet, from vision and strategy to product, delivery, and system design. But the hours go where behavior changes: 10% strategy, 20% culture, 70% execution.

70%

Execution

Let data find the current bottleneck, then ship the smallest system that moves it, in days not quarters. Outcomes are the argument, software is the evidence.

20%

Culture

Review loops and quality gates make iteration fast. Curiosity, experimentation, and psychological safety make failure cheap enough to learn from.

10%

Strategy

Enough vision to aim the work, compressed into decisions and constraints instead of decks.

Now

Urgency

The latest iteration shipped better than the last and still not 100%. That is the point: iterate in production, not in planning.

Stylized grounded portrait of Jan Riethmayer in front of a golden-dusk Berlin: S-Bahn viaduct, Spree bridge and TV tower behind him

Berlin. Hands on the system, not just the strategy: production judgment over demo theatre.

02 / Agentic engineering

Agents are useful when the whole system is designed.

The interesting question is not whether an agent can produce code. It is whether the system around it can keep producing useful behavior: with boundaries, tests, evals, observability, recovery, and adoption.

Operating loop / judgment to adoption
JUDGMENTAGENT SHAPEQUALITY GATEADOPTIONSHIPPEDNEXT ITERATION

Yellow = the loop. Magenta = fails the gate, straight back into iteration. Shipped work ends in the full stop.

Judgment

What should change, for whom, and why now?

Agent shape

Where does autonomy help, and where should humans stay in the loop?

Quality gate

What tests, evals, and reviews prevent speed from becoming entropy?

Adoption loop

Who uses it, what changed, what failed, and what gets corrected?

Practices / how the agentic SDLC is set up, field-tested in production

01

Deterministic gates

Hooks and pre-commit checks enforce the mechanical rules. Nothing depends on an agent remembering.

lefthookClaude hooksdetect-secrets

02

CI mirrors local

One check contract runs identically on the laptop and in CI. Local green means merge green.

GitHub Actionslefthookmise

03

Binary verification

Quality gates score on exit codes, not vibes. No LLM ever judges the gate.

tscESLintsmoke boot

04

Tiered quality bars

Verification depth scales with blast radius. A docs edit never triggers the full battery.

tier registrypaths-filter

05

Multi-bot review

Independent AI reviewers plus a human on every PR, looped until unconditionally green.

CodeRabbitCodexClaude Code

06

Context at the work

Every directory carries its own agent instructions. Review bots get path-scoped invariants.

AGENTS.mdpath instructions

07

Skills as playbooks

Repeatable procedures ship as versioned skills. The skills themselves are eval-tested.

Claude skillsevals.json

08

Evals with ground truth

Prompts are versioned, runs pin BAML prompt and model, results stay reproducible and comparable.

BAMLeval runners

09

Drift ratchet

A deterministic sweep catches what compiles but rots: dead files, duplication, tangled deps.

fallowbaselinespre-push

10

Boundaries agents keep

Ports and adapters enforced by lint at error level. Testable for humans, navigable for agents.

ESLint boundariesdep-cruiser

11

Runtime guardrails

Compliance and PII rules enforced in the tool layer and audit-logged, not just documented.

MCPaudit logDPIA

??

Still learning

This slot stays open on purpose. The next practice earns its place in production.

03 / Proof environment

Built where constraints are real.

Earlybird is the current proof environment: busy users, sensitive data, real decisions, and the need for systems that people can trust. Not a lab, not a demo stage.

Current arena

Venture workflows inside a regulated European fund

Role

VP Engineering at Earlybird

Background

3x founder and CTO; product and engineering led together

Practice

AI-native products, internal systems, technical diligence, quality gates

04 / Writing

Field notes from the point where strategy becomes software.

The writing is where the work becomes legible: product choices, architecture patterns, adoption gaps, trust boundaries, failed assumptions, and the corrections that followed.

01Product judgment in technical systems

02Agentic engineering patterns

03AI-native workflows that survive production

04Technical diligence for AI, data, infra, and cyber

05Failure reports, eval loops, and trust boundaries

06What changes behavior, not just what demos well

Open thread

Build with judgment. Ship with discipline.

If you care about product-minded engineering, agentic systems, or the line between useful AI and production theatre, the thread is open. Build notes, failures, and corrections land at writing.riethmayer.com.