Hey, I'm Yaroslav

Product Engineer

I build things that work. A decade of full-stack product engineering across AI, e-commerce, and enterprise. Currently at Comet ML.

Location Barcelona
Local time 7:42 PM
Let's build something

If it's not useful, it doesn't matter. That's the filter I run everything through.

How I build

Principles I actually follow — not LinkedIn poster quotes.

Products, not tickets

I own problems end to end — from database schema to deploy. The best software comes from engineers who feel the user's pain, not just close Jira tickets.

Speed is a feature

Half a product shipped this week beats a perfect spec next quarter. I use AI at every stage — writing, building, debugging — to ship at a pace that used to require a full team.

Make the team dangerous

The best thing a senior engineer can do is make everyone around them faster. I build tools, set patterns, and ship examples — multiplying output, not hoarding it.

Diagnose before you fix

Don't treat symptoms. Find the root cause, understand the system, then act. Works for architecture decisions. Works for production bugs at 2 AM.

Stay uncomfortable

Medicine, four countries, three tech stacks, open source in a new protocol — I don't optimize for comfort. The best work happens at the edge of what you know.

What I'm building

Shipping core features and developer experience for OPIK — an open-source LLM eval and tracing platform at Comet ML with 18.6K+ stars.

OPIK Platform

18.6K+ stars · 185+ PRs

Shipping core features and developer experience for an open-source LLM evaluation and tracing platform.

Evaluation UITypeScript SDK185+ PRs
My contributions →

Latest posts

Recent thoughts on engineering, tools, and open source.

claude-codeaideveloper-toolsproductivity

Stop Using Claude Code on Defaults

Five Claude Code settings I changed in ~/.claude/settings.json to save tokens, kill hallucinations, and stop approving ls for the 400th time.

aifrontenduxstreamingagentic

Agentic UX Primitives: The Frontend Patterns Nobody Taught You

Streaming, HITL gates, reasoning traces, confidence indicators — the actual frontend patterns behind products like Cursor and Claude.

aimcpcontext-engineeringdeveloper-tools

Context Engineering Ate Prompt Engineering

Prompt engineering hit a ceiling. The skill replacing it — context engineering — is what separates AI-augmented developers from AI-dependent ones.

aiopinionvibe-codingdeveloper-tools

The Vibe Coding Reckoning

92% of devs use AI daily, 41% of code is AI-generated, and the backlash has arrived. The nuanced take both sides are missing.

astrofrontendtypescript

Why I Switched to Astro for My Portfolio

Comparing build times, DX, and performance after migrating from a heavier framework to Astro.

View all posts →