The most common and most likely answer to this crossword clue is the 7 letter word PIONEER
I've seen this crossword clue in The Guardian
P
I
O
N
E
E
R
More clues leading to the result PIONEER
- Developer surrounding unit with buttress
- Trailblazer, one imprisoned by sanctimonious queen
- One breaking into jetty is adventurous type
- Explorer, first person acceptable to poke a lord
- Look to inspire something positive as developer
- Groundbreaker I used in wharf
- Lord going round island aboard launch
- Found small number in support
- I support going without explorer
- Launch one in middle of dock
Buddy explains!

The straight part
We know that "developer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case developer = pioneer.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 PIONEER mean?
PIONEER noun- One who goes before, as into the wilderness, preparing the way for others to follow.
- A person or other entity who is first or among the earliest in any field of inquiry, enterprise, or progress.
- A soldier detailed or employed to form roads, dig trenches, and make bridges, as an army advances; a sapper.
- A member of any of several European organizations advocating abstinence from alcohol.
- A child of 10–16 years in the former Soviet Union, in the second of the three stages in becoming a member of the Communist Party.
- To be the first to do or achieve (something), preparing the way for others to follow.