Flintrock Fund I

Eight companies.
One stack.

Flintrock Fund I has backed eight foundational infrastructure companies that collectively represent the AI application layer's data and ML substrate.

The portfolio as architecture

Every company occupies a distinct load-bearing position in the AI application stack.

MODEL SERVING BentoML ML model serving framework — runs AI models in production FEATURE LAYER Chalk Real-time feature store — millisecond-latency ML features ORCHESTRATION Prefect · Grafbase Workflow orchestration + GraphQL data gateway INDEXING & SEARCH Qdrant · Weaviate · Cocoindex Vector DBs + incremental indexing for AI retrieval ANALYTICAL QUERY · DuckDB Labs — embedded in-process OLAP for the full stack ← application ← substrate
Fund I — all investments

The companies

D
DuckDB Labs
In-Process Analytical Database
Seed 2022

An embeddable analytical query engine that runs complex SQL on local or remote data without a server process. Powers the next generation of data-intensive applications and notebooks.

Q
Qdrant
Open-Source Vector Database
Seed 2023

High-performance vector similarity search engine designed for AI applications. Handles billion-scale embedding retrieval with built-in filtering and payload indexing.

B
BentoML
ML Model Serving Framework
Seed 2022

Open-source framework for building, shipping, and scaling ML-powered services. Abstracts infrastructure complexity from model serving across cloud and on-premise environments.

W
Weaviate
AI-Native Vector Search Engine
Series A 2023

Open-source AI-native database that stores objects and vectors simultaneously. Combines vector search with structured filtering for contextual AI retrieval at scale.

P
Prefect
Data Workflow Orchestration
Seed 2022

Python-native workflow orchestration platform for data and ML pipelines. Observable, recoverable, and developer-first — built to handle real production failure modes.

G
Grafbase
Edge-Native GraphQL Gateway
Pre-Seed 2022

GraphQL data gateway that federates data sources at the edge. Enables AI applications to query multiple backends through a unified, performant schema layer.

C
Chalk
Real-Time Feature Store
Seed 2023

Feature platform for real-time ML models. Lets teams define features in Python and serves them at millisecond latency — closing the gap between model development and production.

C
Cocoindex
Incremental Indexing Engine
Pre-Seed 2024

Indexing engine for unstructured data that updates incrementally rather than rebuilding from scratch. Critical infrastructure for AI systems that operate over live, evolving document corpora.

Portfolio reflects investments made by Flintrock Fund I as of the date of this publication. Stage and year reflect Flintrock's entry point. Past performance is not indicative of future results.