Constraint is a limitation or restriction placed on a system or process that must be satisfied for the system to function properly. In software engineering, constraints are often used to define the boundaries and requirements of a system, such as the maximum number of users it can support, the minimum hardware requirements, or the specific data formats it can handle.

How to use it in a sentence

• As the lead engineer on the project, Sarah spent hours defining the constraints of the system to ensure it could handle the massive scale of Facebook's user base without crashing like Twitter does every other day.

• "I know you want to use that shiny new NoSQL database, but our constraints specify that we need full ACID compliance, so put down the MongoDB and slowly back away," said the grizzled old database architect who still refuses to use anything but Oracle.

If you actually want to learn more...

• Design by Contract: The Lessons of Ariane - This classic article explores how the failure to properly specify and validate constraints led to the infamous crash of the Ariane 5 rocket, and how the Design by Contract methodology could have prevented it.

• Constraint Programming vs. Mathematical Programming - For those who really want to geek out, this academic paper compares and contrasts constraint programming with mathematical optimization techniques. Perfect for those long nights when you just can't decide which approach to use for your supply chain optimization problem.

• Constraints in Software Design - This recent article explores how constraints can be used to guide software design decisions and ensure system quality attributes like performance, security, and maintainability. A must-read for any architect who wants to sound smart in design review meetings.

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