The AI Infrastructure Stack
Overview  /  Tier I Demand
Layer 03

AI Developer Tooling & Middleware

The picks and shovels for everyone building on top of foundation models.

What this layer does

Between the raw model API and a shippable application sits a stack of glue: ways to store and search embeddings, orchestrate multi-step agents, evaluate model output, observe production behavior, fine-tune on custom data, and label or synthesize training data. This is the AI equivalent of the data infrastructure boom of the 2010s — lots of competing private startups, frequent commoditization, but a few will own real markets.

Almost all private. Public exposure is mainly via Databricks/Snowflake-adjacent tooling and the few platform incumbents (MongoDB, Elastic) that have credible vector offerings.

Sub-categories

Analysis coming soon — will cover: which middleware categories collapse into the foundation labs themselves (eg OpenAI Assistants API absorbing agent frameworks), which become enterprise software companies, and where the public-market trades hide.