I built a machine learning model to predict who leaves tech jobs early. The results surprised me.

A People Analytics study analyzing 205 tech professionals found that early employee attrition is driven more by stalled career momentum than workplace culture. Promotions, internal mobility, and visible growth opportunities were the strongest predictors of retention, while team socialization had little measurable impact.

I went into this research convinced I already knew the answer.

After more than a decade in People Analytics, the last few years at Meta, I had a working theory about why tech employees leave their jobs within the first year. Two things, I believed, were doing most of the damage: whether someone was getting promoted, and how often they were socialising with their immediate team outside of work. The first felt obvious. The second felt like the kind of human factor the industry consistently underweights.

I was half right.

When I surveyed 205 tech professionals globally and trained a machine learning model to predict early attrition ...