Tech Stack

AI Engineering (AIE) builds apps using existing foundation models. APIs made them easy to use. AIE exploded.

3️⃣ Three Layers

Three layers make the AI stack:

1. Application Layer- Product companies turn capabilities into user value

2. Infrastructure Layer - Infra companies make capabilities accessible and scalable

3. Model Layer - Model companies create foundational capabilities

Big Tech companies and AI startups may focus on all three layers

whereas AI Engineering in other companies focuses on the Application layer.

🏢 Companies

Product Companies build user-facing apps. Deploy fast. Iterate based on feedback. Examples include Cursor, GitHub Copilot, Devin AI, Lindy, Cursor, and Bland.

Infrastructure Companies provide tools for product teams. B2B focus. Built for scale and reliability.

• Inference Providers serve models through APIs. OpenRouter, Together AI, Cohere, Amazon Bedrock, Hugging Face, Google Vertex AI, Replicate, Fireworks AI.

• Database Providers serve AI-optimised retrieval. Pinecone, Weaviate, Qdrant, Chroma.

• Observability Providers monitor and evaluate performance. Galileo, Phoenix, Langfuse, Opik, LangSmith.

• Evaluation Frameworks assess various aspects of LLM performance, such as correctness, faithfulness, and safety, using metrics like answer relevancy, hallucination detection, and task completion

Model Companies create foundation models. Google, Meta, Anthropic, OpenAI, Mistral AI, xAI, Stability AI.