Expert-led video courses covering legacy code modernization strategies and essential design patterns.
Master proven strategies for safely modernizing legacy systems without breaking production.

An overview of legacy systems, why they persist, and strategies for modernizing them.

A comprehensive guide to safely modernizing legacy systems using the Strangler Fig Pattern.

Learn how to safely swap dependencies in production without breaking anything.

Run old and new implementations side-by-side to validate correctness before switching over.

Master gradual rollouts, safe deployments, and risk-free releases using feature flags.

Learn proven techniques to safely add tests to untested legacy code and enable confident refactoring.

Learn Michael Feathers' concept of seams for testing legacy code without breaking production.

Master zero-downtime database migrations using expand-contract, dual writes, and backward-compatible schema changes.
Learn essential design patterns with clear examples and practical applications for legacy code.

Learn the Decorator design pattern for adding behavior to objects dynamically without inheritance.

Understand the Observer design pattern for building event-driven systems and reactive applications.

Master the Singleton design pattern - when to use it, when to avoid it, and why it's controversial.

Learn the Factory design pattern for creating objects without tight coupling to concrete classes.