Design pattern

Config-driven use-case engine

Use cases stored as versioned database records. New use cases ship with no code changes, and deterministic steps skip the LLM.

The problem

Each new review type was a hard-coded workflow. Adding one meant new code, a new deploy and more tokens, even for steps that only needed a fixed query.

The approach

• Three tables describe a use case, its ordered queries, and the mapping between them; a flag marks which steps need LLM reasoning.
• An intent classifier routes each question to a predefined template, dynamic text-to-SQL, or a clarifying question.
• Steps that need no reasoning run as plain SQL and fill templates directly; the LLM only writes the summary and judgment.

What I learned

• Moving behaviour from code into configuration makes an agent faster to extend and easier to review.
• The cheapest LLM call is the one you don't make.