My earlier article titled "Free Will is an illusion" provoked a thoughtful discussion on the philosophy subreddit from which I learned a lot, but then later it was removed. And quite understandably so because absolute determinism is a frightening thought for most humans, our freedom to "will" sort of defines who we are as humans and people can easily get intolerant towards any other alternative views.
In life, we often struggle between two or more conflicting ideas while taking decisions, and a lot of deliberation and pondering happens about what decision to take (like there are flow-charts within a flowchart or functions calling other functions or subroutines). At the end, our thought process arrives at a decision and again, this thought process and deliberation is definitely an experiential proof of free will from the human-centric view.
However, at the universe-centric or cosmic level, this decision may still have been determined already. Remember, the program's path and the output its going to print is already determined before actually running the program on the computer! This is assuming there are no external factors like user inputs. If we were to allow for user inputs in the analogy, this becomes a bit more complex and its difficult to say whether perfect determinism exists or not even at the cosmic level. Some things to ponder here: