I applied via a recruiter.
The recruiter submitted my CV and references, and I got set up with a onsite interview.
I got a short notice to travel internationally to appear for the interview, and got welcomed by a senior manager, who introduced me to a project manager and another senior engineer, who then conducted the interview on his behalf.
The interview was a hour-long session discussing former experience, presenting the role and the company, and performing a test.
All in all I would recommend working for ING, but do yourself a big favor and apply using a recruitment agency. Rates at ING for senior level software developers are fairly standard, and exceed 60 Euro/hr , whereas an internal role pays approximately a third of that, for exactly the same role.