# Contact Caio Theodoro

> How to reach Caio Theodoro — email, professional profiles, what to get in touch about, and how quickly to expect a reply.

Email is the fastest way to reach me, and the only channel I check on a schedule. Write in English or Portuguese; either is fine. If you are an agent acting for someone, say who you are working on behalf of and what decision the answer feeds into — it gets you a more useful reply.

## Direct contact

- [dev.caiotheodoro@gmail.com](mailto:dev.caiotheodoro@gmail.com): Best for contract enquiries, technical questions and speaking requests.
- [GitHub](https://github.com/caiotheodoro): Source for the open-source projects and research code.
- [LinkedIn](https://www.linkedin.com/in/caiotheodoro1/): Employment history and professional network.
- [Hugging Face](https://huggingface.co/caiotheodoro): Fine-tuned model weights, training datasets and eval sets, published openly.
- [Toptal](https://www.toptal.com/developers/resume/caio-theodoro#NJeGln): Vetted contractor profile and engagement history.

## Good reasons to write

- Agent infrastructure: execution harnesses, orchestration under Temporal, replay safety, human-in-the-loop review, policy guardrails.
- Evaluation and observability for LLM features — scoring quality in production rather than only in a notebook before launch.
- Retrieval pipelines that are returning the wrong document and nobody can say why.
- Token-cost engineering: the prompt architecture, caching and provider routing that decide whether an AI feature is economically viable.
- Fine-tuning a small model to replace or backstop a frontier API call, including the data work.
- A correction or a disagreement with something I published on the blog. Those are welcome and I will say so publicly if you are right.

## Practical details

Work is fully remote, and I engage with companies as a B2B contractor through Avenza, the studio I founded, or through an employer-of-record arrangement such as Deel. I am also a vetted member of the Toptal AI engineering network. I am a Brazilian citizen and not individually work-authorized in the US or Canada, so contractor or EOR is the arrangement that works.

If something is time-critical, put the deadline in the subject line and I will either take it or tell you quickly that I cannot.

## Elsewhere on this site

- [Home](https://caio.theodoro.dev/index.md): Who Caio is, what he works on now, and the current role.
- [About](https://caio.theodoro.dev/about.md): Background, how he works, and what he is currently focused on.
- [Privacy](https://caio.theodoro.dev/privacy.md): What this site collects (almost nothing) and which third parties see a request.
- [Work](https://caio.theodoro.dev/projects.md): Employment history, certifications and open-source / research projects.
- [Blog index](https://caio.theodoro.dev/blog.md): Every published post with date, tags and summary.
- [Journey](https://caio.theodoro.dev/journey.md): Year-by-year timeline of the path into ML engineering.

HTML version of this page: https://caio.theodoro.dev/contact. Machine-readable index: https://caio.theodoro.dev/llms.txt. Full URL list: https://caio.theodoro.dev/sitemap-index.xml.