About AntJanus
Antonin Januska · Boulder, Colorado
Portrait of Antonin Januska against greenery

Hi, I'm Antonin.

Staff Engineer building AI-backed systems, engineering standards, and the workflows that let teams ship serious software.

Role
Staff Software Engineer
Location
Boulder, Colorado
Building
20+ years
Blogging
Since 2012
Open source
600+ GitHub stars

Overview

Staff engineer focused on the infrastructure production LLM systems run on: evaluation harnesses, multi-provider dispatch, rate-limit handling, and guardrails on model output.

Principles

  1. A deployed MVP is worth two prototyped.
  2. Dance like nobody is watching, code like everybody is.
  3. Today's fashion is tomorrow's legacy.
  4. Debugging becomes easier if you first admit that you are the problem.
  5. The best code is no code at all.

See the proverbs project →

Beyond Code — The rest of the operating system

Antonin hiking in Colorado
PhotographyI shoot animals, landscapes, people, and street scenes. The camera is how I stay observant.
FictionI write AI-themed fiction and short stories when technical writing is not enough.
Podcasts & GamesI have opinions about Final Fantasy, narrative design, and the overlap between games and technology.

What I work with nowThe stack changes. The throughline doesn't. I'm usually working where backend systems, product delivery, and AI workflows collide.

AI & LLM SystemsMeasuring model output, routing it across providers, and trusting none of it by default.
  • LLM Evaluation & Judge Grading
  • Multi-Provider LLM Dispatch
  • Token Budgeting & Rate-Limit Engineering
  • Structured Output & Guardrails
  • Model Context Protocol (MCP)
  • Agent Tooling & Orchestration
LanguagesPython on the backend, TypeScript for everything else, SQL wherever the data lives.
  • Python
  • TypeScript
  • SQL
Platforms & ToolsAsync services on Kubernetes, databases picked per job, front ends in React or Svelte.
  • FastAPI
  • Redis
  • Postgres
  • SQLite
  • Kubernetes on Azure
  • React & Next.js
  • SvelteKit
LeadershipSetting technical direction and standards, then reviewing what ships against them.
  • Technical Strategy
  • Engineering Standards
  • Cross-Team Delivery
  • Code Review
  • Mentoring

Selected work

I help teams implement AI-enabled product work, sharpen engineering practices, and build systems that survive real usage.

Get in touch →