I always fantasized on the mysterious (and admittedly cool) job of LEGO designer. Is there anyone who knows what it takes?
There's a nice interview with LEGO Designer Mark Stafford on The Brothers Brick:
From LEGO fan to LEGO set designer - the Mark Stafford interview
The basic process was:
The position was advertised, and Mark's portfolio was sent in. He was then invited to a two day recruitment workshop along with a number of other candidates.
I've also read other interviews such as this one from The LEGOLAND Discovery Center asking about how Alex Bidolak became a LEGO Master Model Builder, and he came in through the competition route.
Pierre Normandin followed the path of "well-known AFOL doing tremendous sets" to "AFOL invited by LEGO to participate in secret projects from time to time" to "Actual LEGO designer" (I'd like to say "demigod", but he tends to frown at me when I do that). He was also one of the first groups of LEGO Ambassadors.
But in any case, the most important criteria is, you have to be a tremendous builder. The next step is to make LEGO know about you one way or the other, but if you are a tremendous builder, chances are they will. Then, you have to inquire about job openings and of course, apply. In that respect, I think his path is similar to Mark Stafford's.
LEGOland parks sometimes fill they openings through competitions, but I don't think Billund does that.
Edit: by the way, the job postings aren't in any kind of secret place, but quite easy to find on the LEGO web site (I think they're in category "Product Design/ Development"). Of course if they happen to search for candidates for other jobs in your own area of expertise, maybe being already in house is a good path to reach the designers team, too.
I participated in the Master Builder competition. Winners were potentially offered jobs as Builders and Master Builders. The position was advertised on the LEGO job boards and the competition in question was held in LEGOLAND California.
