The false negative rate of the hiring strategy you advocate would be significantly higher that the traditional programming interviews. There certainly is a fraction of otherwise competent programmers who would fail to write the linked list code because of the interview conditions (stress, time pressure, whiteboard etc.). What is that fraction? 50%? 70%? I'm guessing no higher than that. Now, what is the fraction of competent programmers who haven't written any open-source code? I'm guessing 95%.
Also, the cost of inspecting carefully enough someone's open-source code is way higher than evaluating their answer to an interview question.
Also, at the risk of stating the obvious, if a significant fraction of employers started looking at the candidates' open-source contributions, all new grads would start producing open-source-spam projects, further decreasing the usefulness of this signal.
Also, the cost of inspecting carefully enough someone's open-source code is way higher than evaluating their answer to an interview question.
Also, at the risk of stating the obvious, if a significant fraction of employers started looking at the candidates' open-source contributions, all new grads would start producing open-source-spam projects, further decreasing the usefulness of this signal.