[cabaalis]

I think the reliance on open source work is too heavy. Plenty of amazing engineers have done work at organizations serving millions of customers but have not made contributions to open source. A portfolio is mentioned but is at the bottom of the list of importance, and even noted as such. The author mentions company blogs. At decent sized organizations these could be written by the marketing departments, little regard to the engineers.

[uladzislau]

Open source contributions shouldn't be a deciding factor as I've seen a few very active open source devs unable to do the commercial work on the proper level. On the other hand, lack of open source meaningful activity is a red flag.

[chrisloy]

Author here - completely agree with you. I think the presence of these things can be a nice shortcut to establishing expertise, but lack of them does not imply lack of expertise. These are just suggestions of things to look for, and it certainly isn't my intention that people be ruled out because of an empty GitHub profile. I hope that isn't what it sounds like.