Hey, I'm Yaroslav
Product EngineerI build TypeScript SDKs, APIs, and product workflows for developer tools. Currently at Comet ML.
Let's build somethingI turn ambiguous expert workflows into reliable product surfaces, typed SDKs, APIs, and reusable abstractions.
How I build
Principles I use when product ambiguity meets engineering detail.
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
A narrow product slice shipped this week teaches more than a perfect spec next quarter. I use AI-assisted workflows for writing, building, and debugging, while keeping the standard clear: explicit tradeoffs, working software, and fast feedback.
Make the team faster
The best thing a senior engineer can do is raise the pace and quality around them. I build tools, set patterns, and ship examples that make good decisions easier to repeat.
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
Building product workflows and developer infrastructure for OPIK — an open-source LLM evaluation and observability platform at Comet ML with 19K+ stars, including Ollie assistant workflows, SDK surfaces, and debugging loops.
OPIK Platform
Building OPIK product workflows, typed SDK surfaces, integrations, and Ollie assistant infrastructure for LLM evaluation and observability.
Latest posts
Recent thoughts on engineering, tools, and open source.
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.
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.
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.
The Vibe Coding Reckoning
AI coding tools changed the pace of software work, but production engineering still comes down to understanding, review, and ownership.
Why I Switched to Astro for My Portfolio
Comparing build times, DX, and performance after migrating from a heavier framework to Astro.