Recruiting engineers is hard. It’s one of those things that you also just have to get done if you’re a technology startup. Some of the best engineers in the world who think dynamically and work hard to make something happen work at startups. If you’re a startup, those are the kind of people you want (as opposed to 9 to 5’ers at large companies).
A good way to find these folks is to get organized and start tracking startups or companies that get acquired, track the date of those events, and then set your self reminders to talk with those folks around the two and three year anniversary of those deals.
In general, it’s good practice to meet engineers at startups that get acquired pretty much the day after so as to get a jump start and build a relationship, but realistically if the acquirer is smart the best engineers will be incentivized to stick around for 2 or 3 years. Many will leave sooner, few will stay forever. The same goes for potential candidates in other areas such as sales. I’ve noticed scrappy contingency recruiters do this in the past informally, whereby they’ll say things like “I think folks at company X are probably ready to leave, so we’ll focus on them.”