der Programmierer
programmer
A person whose job is to write and develop computer programs, software, or websites.
Der Programmierer arbeitet an einer neuen App für Mobiltelefone.
The programmer is working on a new app for mobile phones.

programmer
Loading your saved state.
programmer
A person whose job is to write and develop computer programs, software, or websites.
Der Programmierer arbeitet an einer neuen App für Mobiltelefone.
The programmer is working on a new app for mobile phones.

The word is derived from the verb 'programmieren' (to program). The ending '-er' is often used in German to refer to a male person who performs a particular activity.
Ein guter Programmierer muss logisch denken können.
A good programmer has to be able to think logically.
'Der Programmierer' (the programmer) belongs to a word family with the verb 'programmieren' (to program) and the noun 'das Programm' (the program). If you know one of these words, you can understand the others more easily.
Er lernt gerade, wie man ein Computerprogramm programmiert.
He is currently learning how to program a computer program.
Common formulations are 'als Programmierer arbeiten' (to work as a programmer) or 'Programmierer bei' (programmer at) followed by a company name. People also speak of a 'Team von Programmierern' (team of programmers).
Sie arbeitet seit fünf Jahren als Programmiererin bei einer großen Technologiefirma.
She has been working as a programmer at a large technology company for five years.
developer
'der Entwickler' and 'der Programmierer' are often used very similarly in everyday language when talking about software. 'Programmierer' (programmer) especially emphasizes writing code. 'Entwickler' (developer) sounds a little broader: it can also include planning, structure, testing, and further development of a program. So a programmer can be a developer. If you only mean coding, 'Programmierer' is very precise; for the whole process of working on software, 'Entwickler' often fits better.

Der Programmierer hat den Code vor dem Termin noch einmal geprüft.
The programmer checked the code once more before the appointment.
Die Entwickler besprechen am Abend die nächsten Schritte für die neue Lern-App.
In the evening, the developers discuss the next steps for the new learning app.