Business Logic
What is business logic?
Business logic refers to the rules, processes, and workflows that define how a business operates and makes decisions—the specific way your company handles tasks, applies constraints, and manages relationships between different parts of a system. This can include both automated processes (code that handles business operations) and rules embedded in products (like pricing dependencies, access restrictions, or workflow constraints). Business logic often reflects domain-specific edge cases and unusual situations that aren't obvious from technical requirements alone.
How does business logic appear in products and APIs?
Business logic manifests as the rules that govern how features behave and interact. For example, a learning platform might have business logic that says "price cannot be greater than zero for non-paid courses" and "students can't be unenrolled from free courses." These rules seem straightforward individually, but they can create complex interactions—like what happens when you try to change a paid course to enrollment-closed while preserving its price.
In APIs, business logic determines what operations are allowed, what data dependencies exist, and which features are available at different pricing tiers. A Slack API might restrict user invitation endpoints to Business+ plans—that's a business logic decision about how the product and business model work together.
Why is business logic challenging when building with AI?
AI tools like Claude Code excel at understanding technical requirements and generating code for standard error handling. But they struggle with business logic edge cases—the unusual situations that arise from how your specific business operates. These edge cases require deep domain knowledge to identify and test properly.
For instance, an AI might correctly handle a "user not found" error code, but it won't anticipate that your API returns incorrectly formatted data in certain business scenarios unless you explicitly tell it. This means when working with AI on business systems, humans need to identify and communicate business logic edge cases while letting AI handle the more predictable technical implementation.
Learn more:
- Product in Practice: Getting Started with Several APIs (And the Challenges I Faced)
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- 21 Ways to Use AI at Work (And Build Your AI Product Toolbox)
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