When interviews and references leave you with ambiguity about a candidate, move beyond conversation. Invite them to analyze or work on a live investment or project. Observing their thought process and how they "underwrite" a decision provides unparalleled clarity on their actual abilities.

When hiring senior engineers, the crucial test is whether they can build. This means assessing their ability to take a real-world business problem—like designing a warehouse system—and translate it into a tangible technical solution. This skill separates true builders from theoretical programmers.

Instead of treating a resume as a list of facts, frame interviews around the story it tells. Ask "why" behind each job change and project choice to understand the candidate's motivations, self-awareness, and decision-making process. This reveals far more than a list of skills and accomplishments.

To verify if a job candidate truly solved a problem they're describing, listen for emotion. Someone who was merely present will recount the facts. The person who actually did the work will re-experience and convey the specific emotions tied to the struggle and the eventual breakthrough.

To gauge an expert's (human or AI) true depth, go beyond recall-based questions. Pose a complex problem with multiple constraints, like a skeptical audience, high anxiety, and a tight deadline. A genuine expert will synthesize concepts and address all layers of the problem, whereas a novice will give generic advice.

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.

Ditch standard FANG interview questions. Instead, ask candidates to describe a messy but valuable project they shipped. The best candidates will tell an authentic, automatic story with personal anecdotes. Their fluency and detail reveal true experience, whereas hesitation or generic answers expose a lack of depth.

Many candidates claim credit for their team's or company's success. A key interview trap to avoid is failing to distinguish who was a key contributor versus who was just 'on the team' when success happened. Diving deep into specific problems reveals who actually did the work.

Instead of broad questions, Musk drills down into a single problem, often one he knows well, to gauge a candidate's depth of knowledge and detect if they are exaggerating their contributions. This 'video game' approach tests how many layers of a problem a candidate can get through.