Let’s take a look at the following piece of code: fun search(query: String): List<String> { val allItems: List<String> = ExternalSystem.fetchAllItems() val filtered = allItems.filter { it.contains(query) } val reordered = filtered.sortedWith(object : Comparator<String> { override fun compare(lhs: String, rhs: String): Int { if (lhs == query) { return -1 } else if (rhs == query) { return 0 } return lhs.compareTo(rhs) } }) return reordered } From a behavioral point of view, this code has no problems.

Intro Quite often in software development, we come to a point where we have to alter some code, whether to make it easier to read and understand or to add a new feature. Recently a friend of mine posted a piece of code in a public Slack channel, and he asked for resources that would help him improve not only that particular code but any legacy code in general. I’m very thankful that he asked that because I took it as a motivation to record a series of screencast videos where I explain and demonstrate a bunch of techniques that everyone can learn and use in their daily job.