AntJanus®

(04) AboutStaff Software Engineer · Boulder, Colorado

Hi, I'm Antonin.

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

Portrait of Antonin Januska against greenery
Summary

Trust nothing by default.

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

LinkedIn ↗GitHub ↗
20+Years building
2012Blogging since
600+GitHub stars
Principles

Five I code by.

See the proverbs project →
  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.
Capabilities

What I work with now.

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

01

AI & LLM Systems

Measuring 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
02

Languages

Python on the backend, TypeScript for everything else, SQL wherever the data lives.

  • Python
  • TypeScript
  • SQL
03

Platforms & Tools

Async services on Kubernetes, databases picked per job, front ends in React or Svelte.

  • FastAPI
  • Redis
  • Postgres
  • SQLite
  • Kubernetes on Azure
  • React & Next.js
  • SvelteKit
04

Leadership

Setting technical direction and standards, then reviewing what ships against them.

  • Technical Strategy
  • Engineering Standards
  • Cross-Team Delivery
  • Code Review
  • Mentoring
Selected work

Proof.

  1. 01cc-dashProjectTypeScript · MCP
  2. 02SkillboxProjectClaude Code · Agent tooling
  3. 03Agent CompilerProjectCLICLI that embeds agent skills into CLAUDE.md and fails CI when the embedded content drifts.
  4. 04Using Git Worktrees to Parallelize AI AgentsWriting2026-01-30
  5. 0517 Side Projects I Built With Claude Code in Two MonthsWriting2026-02-23
  6. 06Programmer's Proverbs★680
Beyond code

The rest of the operating system.

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

Get in touch.

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

Get in touch