Kotlin Meetup Lisbon - Mutability: Necessity or Habit

On October 3rd, 2024, the Kotlin Lisbon Meetup held its 9th edition, marking the first gathering after the summer break. The event took place at the Mercedes-Benz.io offices in Lisbon. The meetup featured a packed agenda and brought together Kotlin enthusiasts for an engaging evening.

Paulo Pereira delivered a presentation titled Kotlin Meetup Lisbon - Mutability: Necessity or Habit. Kotlin, a language designed to emphasize immutability alongside mutability, requires programmers to decide at the point of declaration: variable or value? This approach contrasts with languages like Java, which default to variables and inherently presume the use of mutations. During the presentation, Paulo examined the relevance of mutability in modern software development, questioning whether it is a practical necessity or simply a habit ingrained in the mindset of imperative programmers. He also discussed the implications of choosing immutable data by default and the potential gains or losses from challenging the reliance on mutations.

The session explored these questions from a historical perspective and used simple, practical examples to highlight the merits and trade-offs of immutability as a fundamental design principle in software development.