Table Module Pattern Explained | One Object Runs a Whole Table

How do you run business logic over thousands of rows without minting an object for every single one? That's the problem the Table Module Pattern helps solve. In this video, we explore the Table Module Pattern, an enterprise pattern where a single object holds the business logic for an entire table, and methods take an id to say which row to act on. You'll learn: What the Table Module Pattern is What problem the Table Module Pattern solves Why one tiny object per row gets expensive at scale How one module wraps a whole record set of rows How methods take an id to pick out the row to act on A practical example of the Table Module Pattern The difference between Table Module and Domain Model The trade-off of shared logic versus one rich object per row When to use the Table Module Pattern The benefits and trade-offs of using Table Module The key idea is simple: One module. Every row. Just pass the id. Table Module is particularly useful when your data already arrives as a tabular record set, when a full domain model would be overkill, or when you want cheaper logic over many rows — like a Contracts module computing recognized revenue for any contract by id, or an Orders module applying shared discount and reorder rules to whichever order or product row you point it at. This video is part of the System by Design series, where we explore software design patterns, system design, software architecture, and engineering best practices. The goal isn't just to memorize patterns. It's to understand the problem they solve, why they work, when to use them, and the trade-offs they introduce. Learn the patterns. Understand the principles. Design better systems. #TableModulePattern #EnterprisePatterns #SoftwareEngineering