Crack Scala Interviews: 3 Questions Every Spark/Scala Engineer Should Know

"When it comes to Scala interviews, the trick isn't just solving problems - it's solving them the Scala way.Interviewers are often less interested in whether you can code something and more curious about how you think, use language features, and write clean functional code. In this article, I'll walk through three interview-style Scala questions. Each question is designed to test a different dimension of your Scala skill set - from string manipulation to functional collections and stack-based problem solving."

"✅ Scala Solution object FirstOccurrence { def strStr(haystack: String, needle: String): Int = { if (needle.isEmpty) return 0 haystack.indexOf(needle) } def main(args: Array[String]): Unit = { println(strStr("sadbutsad", "sad")) // 0 println(strStr("HelloWorld", "HelloHi")) // -1 }} 💡 Explanation Scala's indexOf method is efficient and directly gives the first match. Returning -1 when not found aligns with expected behavior. 👉 What the interviewer learns:This checks whether you know string operations in Scala, can think about edge cases (empty strings), and prefer built-in idiomatic solutions instead of reinventing the wheel."

Three Scala interview problems target different skill areas: substring search, binary array sorting, and stack-based problem solving. Use String.indexOf for the first occurrence and return 0 for empty needle and -1 when absent. Sort a binary array efficiently with arr.sorted to leverage built-in ordering. Emphasize idiomatic solutions and edge-case handling. Use functional collections and concise methods to express intent and performance. Stack-based approaches evaluate nested structures and require explicit push/pop logic. Interview evaluation focuses on problem-solving style, language feature use, clean functional code, and consideration of corner cases and efficiency.

Read at Medium