I feel your pain, as someone in their mid-30s, and also a new dad. It's trite to say that it's hard to make friends in your 30s but it really is true. Between career, family, and just day-to-day life, it's really hard to form connections that are any more than just superficial.

What works for me is finding communities. I participate in Toastmasters, which meets every week (one meets twice a month), and it's a good way to make connections with people and get to know them better. It's also fun because there's people of many walks of life. Retirees, college students, business owners, executives, everyone in between. It's a great way to meet people I probably wouldn't have otherwise met in tech circles.