An Ether “Core Dev” is someone who is an expert and has experience with networking, cryptography, databases, virtual machines, security, system operations, among other things. Of particular focus is people with knowledge about how best to secure the network. Nobody can do all of these things. It takes a team. So a person’s rank should be determined by how much of an expert they are at any or all of these things.
Ether Core Devs can rank each other in this topic to provide a quantitative measure of expertise as an Ether Core Developer. The focus is on the expert’s ability to understand what is required to secure the core ether network.
The expert topic is used by the “Ether Core Dev” canonizer algorithm. The algorithm is a “Peer Ranking algorithm” It uses 2 passes. The first pass is a popular consensus pass to determine who the community thinks are the experts. So everyone is encouraged to participate by ranking who they believe are the best experts at securing the Ethereum core network. As with all bottom-up systems, the more people that participate, by ranking their top 10 experts, the better the amplification of the wisdom of the community.
This algorithm and topic are part of the Ethereum Consensus Project