I see you point colourblindgeek, and in some ways I agree - but I also agree with those that did not receive any communication after Stage 2.
Many companies I have applied to (and worked for) such as Exxon, BP, British Airways and others will always let candidates know whether they have progressed to the next stage or not - though they may not always give a reason (and that I can completely understand!)
I don't think it's entirely unreasonable to have expected at least a BCC email with "Thanks but no thanks ..." or maybe just a disclaimer to all applicants, advising them that no response means the same. All the companies I have worked for or applied to, do this.
Can understand that TCX were most probably inundated with responses - perhaps more than they could reasonably process with the resources they had available.
I didn't get an invite to Stage 2 - fair enough, and best of luck to those still in the game.
