I'm about to start looking for a new job. How would you go about building connections to companies you're interested in, outside attending relevant meetups and conferences?

People hate it, but there are some really good recruiters on linkedin. With some digging, you can find out what recruting firm a company is using. You also have to weed out the junior recruiters trying to connect with everyone on there. Having contacts with a few good recruiters can really go a long way. How to identify? Usually, they will message you with a specific oppurtunity, and will respond with the actually job req when quiried. Caveate is; I say this as someone with a lot of years of experience, so someone who's entry level or green may not be targets of these people.