used with a singular antecedent to refer to an unknown or unspecified person
// An employee with a grievance can file a complaint if they need to.
// The person who answered the phone said they didn't know where she was.
Previous description implies developers are only male, but that is not true.
From https://www.merriam-webster.com/dictionary/they:
Previous description implies developers are only male, but that is not true.