I grew up in Geneva Switzerland and on a visit there last year I was asked what I do and completely drew a blank. I eventually said "programmeur" but that just means "programmer" which could be anything. But as a Software Engineer I build software front to back using a variety of technologies. I googled it but apparently "Ingenieur de logiciel" is not really a thing? I'm so confused there's no straightforward "this is what software engineers are called in france".
Programmeur is not that much used nowadays.
I would suggest one of:
Développeur (widely used term)
Ingénieur en développement logiciel (a bit formal)
Ingénieur en génie logiciel (to be used in a CV more than a conversation)
Pôle Emploi is reporting more than 80 different names for this occupation and its variants (toggle the Appellations métier + icon).
Here in Quebec we use
I cannot speak for other francophone countries, but a quick search on different french job search websites gave me a fair amount of Ingénieur logiciel. Actual people from France could confirm.
It is in the same vein as
Computer engineer > ingénieur informatique
IT engineer > ingénieur TI
Same thing with non-IT fields:
civil engineer > ingénieur civil
mechanical engineer > ingénieur mécanique.