In the positives of Phind:
* Phind was able, even eager, to recommend specific libraries relevant to the implementation. The recommendations matched my own research. GPT-4 takes some coaxing to get it to recommend libraries. Phind also provided sample code using the libraries it recommended.
* Phind provides copious relevant sources including github, stackoverflow and others. This is a major advantage, especially if you use these AI assistants as a jumping off ground for further research.
* Phind provides recommendations for follow on questions that were very good. One suggestion to the Phind team: don't remove the alternate follow on questions once I select one. A couple of times it recommended a few really good follow up questions but as soon as I selected one the others disappear.
In the positives of GPT-4:
* GPT-4 gave better answers. This is my subjective opinion (obviously) but if I was interviewing two candidates for a job position and using my question as the basis for a systems-design interview then GPT-4 was just overall better. In many cases it added context beyond my question, recommending things like logging and metrics for example. It seemed to intuit the "question behind the question" in a much better way than the literal interpretation of Phind. This is probably highly case-dependent, sometimes I just want an answer to my explicit question. But GPT-4 seemed to understand the broader context of the question and replied with that in mind leading to an overall more relevant response.
* GPT-4 handled follow-up questions better. This is similar to the previous point - but GPT-4 gave me the impression of narrowing down the scope of the discussion based on the context of my follow-up question. It seemed to "understand" the direction of the conversation in a way that felt like it was following context.
NOTE: this was not a test on coding capability (e.g. implementing algorithms) but on using these AI coding assistants as sounding boards for high-level design and architecture decisions.