The IBM ranks are inaccurate. Fellows are not above DEs. Both are the highest ranks indeed, but of two different tracks. DE is the highest rank of the engineering track, while Fellow is the highest rank of the research track. Fellowship have also be granted to non-research people over the past 20 years, diluting the merit of the title IMHO. Examples of fellows are: John Backus, Gene Amdahl, Ken Iverson, Benoit Mandelbrot, etc.
Both levels may reside in different pay bands, but they are both at the executive level. And DEs cannot become fellows, and vice versa (some exceptions to the rule may have existed).
Both levels may reside in different pay bands, but they are both at the executive level. And DEs cannot become fellows, and vice versa (some exceptions to the rule may have existed).