Research shows work samples are the single highest predictor of a candidate's future success, yet most companies over-rely on conversational interviews. Integrating a hands-on project or work trial provides immense signal for the company and gives the candidate a realistic preview, which also enables powerful self-selection.

Use the maxim, "How someone does anything tells you how they do everything." Assess a candidate's preparation for the interview itself. Their research, note-taking, and follow-up are direct predictors of their future diligence and performance in the role.

Interviewers often form a strong inclination to hire or not hire within the first 10-15 minutes of an interview. This is typically when they ask broad, high-scope questions. While the rest of the interview serves to confirm this initial judgment, it's very difficult for a candidate to recover from a poor first impression.

At Meta, an interviewer's stated confidence in their hiring decision correlates more strongly with a candidate's future on-the-job performance than the raw interview feedback. This suggests that calibrated interviewers develop an intuitive 'gut check' that captures a candidate's potential for success beyond the formal rubric.

Hiring managers are biased by "interview ability"—a candidate's charisma. Lou Adler’s 'Four A's' (Affable, Articulate, Assertive, Attractive) seduce interviewers but don’t predict on-the-job performance. The only antidote is to focus on a clear, objective scoreboard of past and expected performance.

Interviews are often misleading. A trusted recommendation from a high-performing employee or contact is a more reliable signal of a candidate's quality than your own interview assessment. This "reference hiring" is a secret weapon for building a strong team.

Salespeople are professionally trained to be liked, a skill crucial for their role but often over-weighted in interviews. This rapport doesn't indicate discipline or process-orientation. Hiring managers must test for performance skills beyond mere likability to avoid this trap.

A common hiring mistake is prioritizing a conversational 'vibe check' over assessing actual skills. A much better approach is to give candidates a project that simulates the job's core responsibilities, providing a direct and clean signal of their capabilities.

Ineffective interviews try to catch candidates failing. A better approach models a collaborative rally: see how they handle challenging questions and if they can return the ball effectively. The goal is to simulate real-world problem-solving, not just grill them under pressure.