Kresimir successfully completed an online Coursera course in Functional Programming Principles in Scala from École Polytechnique Fédérale de Lausanne with distinction. The advanced undergraduate course covered functional programming principles like functions as values, recursion, immutability, pattern matching, higher-order functions, collections, and lazy evaluation using the Scala programming language. The course was taught by Martin Odersky, a professor of computer science at École Polytechnique Fédérale de Lausanne.