I also met my search partner early in college through mutual involvement in an investment group. We ended up roommates senior year, so got to know each other quite well. After school we had separate career trajectories, but stayed in touch. Both of us were looking for a career change late last year, and partnered up for a search. We are hoping to close on our first acquisition within two months (so haven't worked together in the business yet), but a few thoughts based on my experience so far:

1) Partner very early in your ETA experience and search together. You don't want to bring someone in afterwards to partner, otherwise you won't get as much experience working through problems together. How points of disagreement are negotiated and resolved during this process will be a proxy for how you will work together post-acquisition. Communication is key.

2) Try to find someone in a similar career and personal situation as yourself, but with varied experience and aptitudes. Someone much older/younger may result in power imbalances in the partnership (this may be fine for some people). Likewise, someone who can't contribute as much time to the business because of their personal situation may lead to resentment in the partnership (or has to be adequately compensated).

3) Spend time early on mapping out a vision and goals for the partnership. List your own and your partner's strengths and weaknesses, then discuss it with each other. Write down and come to a mutual agreement how you plan to split responsibilities and resolve conflict.

A few questions we personally used to frame some of the vision/alignment discussion. Many other important issues we discussed previously and are not included in this list, so I'll try to make another post at some point with greater detail.

1) What motivates you for ETA? What are your long-term goals?
2) Will you be ready to invest significant time and money in the next 6 months to search for and acquire, and then at least 3+ years co-running a business?
3) Do we want to self-fund this ourselves, bring on external investors for all the capital, or a mix of both?
4) Are you willing to relocate?
5) Do we want to be equal or unequal partners?
6) How big does the business need to be for it to be worth each of our time as equal partners?
7) What are our value-adds as an owners/operators?
8) What does your ideal day-to-day involvement in the business look like?

We're pre-acquisition but there are several signals that gave me conviction that my partner was a good fit. #1 was dedication, we are both committed to making an acquisition as the next step in our careers. We're both "all in" and see this as the only option for fulfilling our professional desires. One thing we both agreed on is it's not just about the money. We have turned down numerous offers for more pay in our current W2 jobs. There's no amount of money or promotion that would convince us from stepping away from an acquisition. #2 was work ethic, we've worked together on projects before and it's hard to find anyone who can match our work ethic. We're both workaholics in the best sense of the word and have families who are supportive and understanding. #3 was compatibility, we have similar hopes and values. We can sit and talk for hours and genuinely enjoy working together. Last but not least, #4 is we complement each other's skills and both bring unique value to the search and eventually operating the business. It's a lot like dating and I would say, when you know, you know.