Custom AI vs. SaaS AI
Custom AI and SaaS AI represent two ends of a build-versus-buy spectrum. SaaS AI is a vendor's model behind a vendor's interface—ChatGPT Enterprise, Jasper, Writer—where you get speed to deployment but inherit someone else's architecture, limitations, and roadmap. Custom AI is a system built for your specific data, workflows, and success criteria, typically combining foundation models with proprietary retrieval layers, custom evaluation pipelines, and interfaces designed for your users. The tradeoff is real: SaaS AI ships in days, custom AI ships in weeks or months. But SaaS AI gives every competitor the same capability, while custom AI can become a durable advantage. The right answer depends on whether the AI capability you need is a commodity or a differentiator. Email summarization is a commodity—buy it. A system that underwrites insurance risk using your proprietary claims data is a differentiator—build it.
Related terms:
Foundation Model
A foundation model is a large AI model trained on broad data at massive scale, designed to be adapted to a wide range of downstream tasks rather than built...
Prompt Engineering
Prompt engineering involves designing and refining inputs—ranging from simple instructions to detailed system prompts with examples, constraints, personas,...
Token
In large language models, a token is the basic unit of text—usually chunks of three to four characters—that the model reads and generates.