The most common and most likely answer to this crossword clue is the 4 letter word APPS
A
P
P
S
Buddy explains!
The straight part
We know that "A part-time programmer's software debuts" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a part-time programmer's software debuts = apps.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does APPS mean?
APPS noun- An application (program), especially a small one designed for a mobile device.
- Application (use, purpose; not a computer program)
- Application (to a college etc.)
- Appetizer
- An appearance in a game (e.g., a player with 10 apps in a season played 10 times)