Fractional CTO at Cookielab, Prague

I help teams build with agents.

I have shipped software since 2004. Engineers today don't write or read the code. Agents do, and our job is to lead them.

Email me See the work

98%of the 705 pull and merge requests I landed in the last 90 days were made by my agents.

My agents
Me

repositories, client and internal: 42
median from open to merge: 38 min
for 90% to merge: 10 h

Selected work

Cookielab, internal · 2026 · in progress

AI first SDLC

Agents already write and review our code. Now I am working on the rest of the process, from a request to working software in production. Some parts already run. The full flow does not exist yet.

2,960AI code reviews on 937 merge and pull requests by 42 authors in 27 repositories, 21 August to 22 September 2026, from usage telemetry. I am the main author of the review tool.

Benchmark: the code review API rewritten from TypeScript in Zig

Same workload on the same 8-core ARM board, three runs each, medians. Zig wins on memory and startup. TypeScript still answers fresh-socket polls faster.

Idle memory

TypeScript: 141 MiB
Zig: 12 MiB

Measure	TS	Zig
Idle memory	141 MiB	12 MiB
Startup to ready	2.0 s	0.43 s
Release image	529 MiB	154 MiB
Signed hooks/s	71	116
Socket poll, p50	10.9 ms	23.0 ms

From the benchmark notes in the tool's repository.

Client · Interim CTO · 2025 to 2026

FaceUp

For about 13 months I was CTO of FaceUp, a whistleblowing platform with 1.3M users in 70+ countries. I moved the team from Scrum to Kanban and brought AI-assisted coding into daily work, first in Cursor, then Claude Code. Then I handed over to an in-house CTO.

3 → 1generations of code in the product, merged into one standard at a team hackathon.

Read the case study

“Together with Cookielab we unified our development and set up the processes our internal team builds on today. Exactly the help we needed at that stage.”

Jan Slama, CEO and co-founder, FaceUp

Startup · Co-founder & CTO · 2022 to 2024

Out of Dark

A startup for monitoring and improving the customer journey, which I co-founded with Shoptet founder Miroslav Uďan, Radek Hudák and Michal Feigler. It grew to about 15 people and closed in 2024, before it found product-market fit.

0 → 1product, launched after eight months of development and testing with hundreds of users. Early customers included Vodafone and T-Mobile.

CzechCrunch on the launch and the closing (in Czech)

Writing

January 2026 · Cookielab blog, in Czech
Engineering in 2026
Small niche SaaS will lose to tools teams build for themselves. Strict checks and a living AGENTS.md matter more than prompts.
March 2026 · Cookielab blog, in Czech
Growing your padawans in the AI era
How our tech leads go through a developer's real agent sessions in 1:1s to coach prompting and suggest skills.

I have blogged since 2008. The older posts, mostly Nette, Doctrine and PHP in Czech, are on vrtak-cz.net.

Experience

2024 to now
Fractional CTO at Cookielab
CTO for Cookielab clients. These days mostly helping our own engineers and client teams work with agents.
2025 to 2026
Interim CTO at FaceUp
2022 to 2024
Co-founder & CTO at Out of Dark

Earlier: backend, SRE and PHP, 2004 to 2024

2016 to 2024
Node.js and TypeScript backend developer, then SRE and Lead SRE at Goodbaby, then Cookielab
Backend for Socialbakers, Kiwi.com and Goodbaby. Production for Cybex SensorSafe, Carvago, Omnetic and Alpha Analytics.
2004 to 2016
PHP developer at Slevomat, Shipito and agencies
Spoke about Nette, starting with Nette on the Road in Hradec Králové in 2011. Wrote the open-source Nella framework.

What my agents write: TypeScript with Effect, TanStack and React at work. Zig, Go and Rust on my own projects.

Side projects: WormHole, an AI gateway, a Slack bot and an upstream T3 Code fix

WormHoleZigalpha, private
Access to SSH, Kubernetes, PostgreSQL, Redis and AWS in the style of Teleport, written from scratch.
AI gatewayGointernal
Lets Cookielab people plug in their own ChatGPT and Claude subscriptions, with usage limits and a self-service UI.
Slack botRustinternal
Cookielab's team bot, with read-only access to GitLab, Jira, Notion and Google Workspace.
T3 CodeTypeScriptmerged #11970
Upstream fix in the agent GUI I use every day: slow Git checks no longer hold up the end of an agent turn.

Off the clock

Home lab

A rack of servers at home. I am deep into self-hosting, and my agents run there too.

Karting

I race in the Sodi World Series. It is how I take a break from IT.

Father

My wife, our two daughters and two cats. The best team I am part of.

Get in touch.

Happy to talk about agents, engineering teams, self-hosting or karting. If you need a whole team, Cookielab, where I work, can help.

patrik@votocek.cz

01Selected work