Clelia Astra Bertelli

Member of Technical Staff @ LlamaIndex • AI Infrastructure • OSS • Technical Education

About Me

I’m Clelia, an Open Source Engineer at LlamaIndex working on AI systems, agentic workflows and developer tooling.

My work sits at the intersection of engineering, open source and technical education: I build OSS projects, maintain widely used AI tooling, and I write and speak publicly about emerging workflows, coding agents, observability, document intelligence and MCPs.

I’ve contributed to projects reaching thousands of developers, maintained components of the LlamaIndex ecosystem, written for companies including Google, Render, Auth0, LanceDB and Qdrant, and created open-source tools adopted by the community.

Writing, Talks & Community

Technical Writing

Articles on coding agents, document workflows and AI infrastructure.

Author of technical articles for LlamaIndex and independently on:

Public Speaking

Talks and YouTube videos around AI and agents.

A selection of contributions:

Community

Building in public.

~5000 LinkedIn followers

800+ X followers

~500 GitHub followers

2.2K+ GitHub stars across projects

Active through blogs, YouTube tutorials, OSS demos and technical talks.

Selected Projects & Open Source

aggit

Repository

Local and S3-backed git-like object storage for AI agents artifacts. Rust-based.

Aggit is git designed for your AI agents.

Add atomic changes, commit them, back them up to a remote S3 server, without never polluting your branch history, and push to GitHub only when you’re satisfied with the result.

PdfItDown

Repository

Convert almost any file to PDF • 20K+ downloads

Python package and CLI for converting heterogeneous formats into PDF workflows for GenAI applications.

Adopted by developers building document pipelines.

sunbears

Repository

Rust-based CSV parsing library for TypeScript, inspired by Polars and Pandas.

Sunbears is a native Typescript library, cross-compiled from Rust.

Able to read a 1.000.000 lines CSV in 0.3s in Node, SunBears is designed to bear the weight of data-intensive workloads for TypeScript backends.

workflows-acp

Repository

Generalist AI agent supporting ACP, MCP and sandboxed execution

Agent framework with support for filesystem tools, memory, TODO tracking, AgentFS and multiple model providers.

agentfs-claude

Repository

Safer coding agents through filesystem sandboxing

Run Claude Code/Codex inside AgentFS rather than real filesystems to reduce destructive operations.

What-a-git-year

Website

Spotify Wrapped for GitHub

Full-stack Go application with authentication, caching, monitoring and analytics.

Experience

LlamaIndex

Member of Technical Staff

May 2025 – present

https://llamaindex.ai

Building AI infrastructure and agentic developer tooling

  • Working on LlamaAgents and LlamaParse Platform (agent capabilities, knowledge base/agentic retrieval capabilities)
  • Maintaining open source projects such as LiteParse and Semtools
  • Producing demo for LlamaParse Platform products, also in partnership with other companies such as Google, Render, Qdrant, LanceDB, Auth0
  • Producing tech content such as blogs and videos, and engaging with the community at conferences and meetups

LegalForLandlords

AI Engineer

Feb 2025 – May 2025

Legal document understanding with AI

Contributed to pipelines processing legal documents through AI agent orchestration.

Natural History Museum Vienna

Bioinformatics Researcher

Oct 2024 – Mar 2025

Genomics & quantitative biology

Researched human-driven impacts on Drosophila population genetics using genome data.

Criad Ltd

Founding Engineer

Jun 2024 – Feb 2025

AI for architecture & design workflows

Early engineering work around AI-powered products for architects and designers.

Collaborations

Build a Smart Financial Assistant with LlamaParse and Gemini 3.1

Co-authored technical article on the Google Developers Blog demonstrating how to combine LlamaParse with Gemini 3.1 to build AI-powered document workflows.

Building Document Pipelines That Actually Scale

Contributed a deep-dive on architecting scalable document ingestion pipelines using LlamaParse, covering deployment patterns and performance considerations on Render’s infrastructure.

Securing AI Document Pipelines with LlamaIndex and Auth0

Partnered with Auth0 to write a guide on adding authentication and authorization to AI-powered document workflows, integrating the LlamaParse Platform services with Auth0’s identity platform.

Smart Parsing Meets Sharp Retrieval — Combining LiteParse and LanceDB

Collaborated with the LanceDB team to demonstrate how LiteParse and LanceDB complement each other for efficient multimodal document parsing and vector retrieval at scale.

The Hitchhiker's Guide to Document AI with LlamaParse and Qdrant

Partnered with Qdrant to publish a practical guide on building end-to-end retrieval AI systems.

Education

University of Pavia

BSc Biological Sciences

2022–2025

Genetics • Bioinformatics • Evolution

Biology degree focused on genetics and computational biology.

Dissertation:

“Exploring Potential Commensality Patterns between Drosophila melanogaster and Homo sapiens in Europe”

Supervised by University of Pavia and Natural History Museum Vienna researchers.

A Little More About Me

Beyond engineering, I care deeply about communication.

I enjoy explaining difficult ideas, writing technical content, speaking publicly and helping developers adopt new workflows.

My interests increasingly revolve around developer tooling and how AI changes software engineering practice.

Outside tech: travel, museums, biology, sports and my cat.