The eternal struggle: Backward compatibility vs. technical debt | Alain Schlesser

Software engineers face the eternal struggle between backward compatibility and technical debt, a constant balancing act that requires deliberate planning and best practices to avoid code complexity and maintainability issues.

Key takeaways
  • Technical debt is the cost of deferring maintenance and repairs.
  • It’s like borrowing from the future to solve a problem now, but it needs to be paid back later.
  • Backward compatibility and technical debt are two opposing forces in software engineering.
  • Backward compatibility keeps the software working with older versions, but it creates technical debt.
  • Forward compatibility is the key to avoiding technical debt and breaking changes.
  • Rebuilding software from scratch can be a good strategy, but it’s not always possible.
  • Best practices can help you code more maintainable and flexible code, but they’re not enough to eliminate technical debt.
  • Deliberate technical debt is created when you plan ahead and know you’ll need to refactor later.
  • Inadvertent technical debt is created when you don’t know better and code faster but less maintainable code.
  • Technical bankruptcy is when a software system becomes so complex and inflexible that it can’t adapt to changes.
  • Code needs to be flexible and adaptable to the changing environment.
  • Interfaces can be kept strict or loose, but a balance needs to be found between the two.
  • Technical debt needs to be repaid, but it’s difficult to estimate when and how.
  • Code complexity increases exponentially as technical debt accumulates.
  • Semantic versioning helps control breaking changes and manage technical debt.
  • WordPress, as a PHP project, has accumulation of technical debt over 15 years.
  • Rebuilding WordPress from scratch is not an option, but the project needs to balance backward and forward compatibility.
  • Software engineering is all about balancing competing forces, and backward and forward compatibility are two of them.
  • Technical debt can be managed, but it’s a constant struggle, especially in rapidly changing environments.
  • Best practices and experience are essential for managing technical debt.
  • The key is to find a balance between backward and forward compatibility, and to plan ahead for future changes.