IB -> Macro Quant

Hey All - Bulge Bracket Structured Finance banker looking to pivot back to my roots (Math / Econ Undergrad, ex-aspiring buyside quant) and wanted to ask all of you some stupid questions. Realize I'm going off the reservation here by attempting to pivot from investment banking to buyside quant (more specifically at a top-down strategy, just to further illustrate the complete 180 I'm looking to make), but think it's time in my career to make a passion-driven decision. My current role, frankly, was an offer I couldn't refuse given the opportunity set I had at the time (~3 years ago).

Anyways, here goes nothing:

- Which funds employ which types (e.g. RenTech seem to be exclusively the latter, AQR the former)? Examples would be extremely helpful.
- Does "quant strategy" automatically imply "systematic," or are some strategies more discretionary (examples would be great here as well)? Are there any in particular that jump out as having very broad mandates and more optionality in terms of ways / asset-classes through which they can express an investment thesis?
- What (if any) are the top quant shops specifically for credit investing?
- Which recruiting firms work on relevant mandates?

- What are the different flavors of "buy side quant" - is it fair to bifurcate as econometrics-focused versus signals-focused? What other buckets would you add?
- Are "econometrician" type quant positions reserved for PhDs in economics, or have you seen cases of undergrads with compelling experience sneaking into these roles?
- Further to the above, if it came down to it, would a Masters in Econ help? (realize these programs are typically not as prestigious as MFEs or MBAs, but in looking through curriculums they appear to check more boxes in terms of personal preferences).

For additional context, will say that while what I'm currently doing would certainly not be classified as quantitative by folks here, it's extremely niche and complex in the context of IB. I've built a strong skillet in cash flow modeling / understanding complex situations (excel and vba, though) and have done some actuarial analyses (won't expand further on that to avoid self-identifying). All of that is to say that while my math brain / programming skills have atrophied in this role, the pendulum hasn't swung completely over to investment banker for me.

Any thoughts or criticisms are welcomed.