[imtringued]

You should grow a second spike. I'm at the point where visual design skills are a greater bottleneck than my computer science skills. I can build purely functional CAD models but man, making them functional AND look good is the real challenge.

[anonytrary]

Agreed. Everyone should aim to have 3-4 spikes they are passionate about. For every spike you have, you become exponentially more of a domain expert at the problems that are at the intersection of those spikes.

[PeterisP]

Yes, proper senior expertise often looks like being a jack of all trades and a master of three or so.

[atla-sh]

Another perk is that you have other spikes to grow for variety to keep you from burning out or becoming disinterested.

[dxdm]

What's a "spike" in this context? This one's hard to google. I'm assuming something like "area of competence", but a more precise definition would be nice to know.

[majormjr]

Check the link from GP. You're correct a "spike" of knowledge is some topic that you specialize in.