Architecting Low-Code AI Solutions
The low-code spectrum on Vertex AI
Low-code does not mean "no architecture." The exam expects you to place a requirement on a spectrum: prompt-only use of Gemini in Vertex AI Studio (system instructions, temperature, top-p, safety filters, structured output); grounding/RAG with Vertex AI Search or RAG Engine over your own corpus; prebuilt task APIs (Document AI, Speech-to-Text, Vision); AutoML for tabular, image, and text models you own; and finally custom training when no managed option fits. Vertex AI Agent Builder and Conversational Agents compose these into an assistant.
Traps that show up in questions
- Grounding vs fine-tuning. If answers must be current, cite sources, or reflect private documents, ground the model. Fine-tuning (or adapters) changes tone, format, and task behavior, not facts.
- Model Garden vs RAG Engine vs Agent Builder. Model Garden is a catalog of models to deploy or tune; RAG Engine retrieves and indexes your documents; Agent Builder builds the end-user experience.
- AutoML vs custom. Questions with "limited ML expertise" and "weeks, not months" point to AutoML or a prebuilt model, not a custom training job.
- "Low-code" still carries governance. Service accounts, Application Default Credentials, quota project, IAM roles, VPC Service Controls, and CMEK apply to every call, including Studio prompts.
- Context limits. Long documents usually need chunking and retrieval rather than a bigger prompt.
Rule of thumb
Change the data before the weights: prompt engineering → grounding/RAG → adapters or tuning → custom training. Each step costs more and takes longer than the one before it, so questions that mention a deadline or a small team almost always resolve at a lower step.
Worked example
A support team wants a chatbot that answers from 40,000 PDFs, must cite the page, and has no ML engineers. Correct path: ingest to a Vertex AI Search data store, build an Agent Builder/RAG Engine app with Gemini, keep a system instruction for tone, and leave fine-tuning out of scope.