The Peter Principle — the observation that people are promoted to their level of incompetence — is most vividly illustrated in the transition from technical expert to people manager. A brilliant engineer who is promoted into an engineering manager role is not being rewarded with a more senior version of what they already do. They are being asked to do something fundamentally different: to achieve results through other people, rather than through their own technical expertise. This requires a set of skills that technical excellence neither develops nor predicts — and failing to test for those skills before making the promotion is an expensive and avoidable mistake.

Why Technical Excellence and People Management Are Orthogonal

Technical expertise rewards depth, personal mastery, and individual problem-solving. People management rewards breadth, emotional intelligence, and the ability to create conditions in which others can do their best work. The cognitive and behavioural skills that produce outstanding technical performance — deep focus, perfectionism, preference for precision, comfort with technical complexity — can actively interfere with effective people management when they're not complemented by interpersonal capability.

A senior developer who becomes an engineering manager and cannot stop debugging code when a team member could do it with guidance is not failing through lack of commitment. They're failing because the skills rewarded throughout their technical career are pulling them toward individual contribution and away from the leadership behaviours their new role demands.

The Signals That Suggest Leadership Readiness — or Its Absence

When evaluating technical candidates for management roles, look for these differentiated signals:

• Enjoyment of teaching vs. doing: Does the candidate describe satisfaction from helping a colleague solve a problem, or only from solving it themselves? This reveals whether coaching has natural appeal.
• Response to ambiguity: Technical roles have increasingly clear success criteria. Management roles are often ambiguous. Does the candidate demonstrate comfort navigating situations without a "correct" answer?
• Credit attribution: Does the candidate naturally acknowledge team contributions, or do their success stories centre primarily on their own capability?
• Conflict comfort: People management involves navigating interpersonal conflict constantly. Do they describe avoiding difficult conversations or engaging them?
• Interest in people: Perhaps most simply — do they appear genuinely curious about and interested in the people around them, or primarily in technical problems?

Pre-Hire Leadership Testing for Technical Candidates

Leadership assessments for technical candidates should move beyond their domain expertise and specifically probe people-management instincts. Scenario-based leadership assessments — presenting situations involving team underperformance, cross-functional conflict, resource constraints, and individual development challenges — surface whether candidates have the interpersonal orientation that management demands.

This is especially critical for internal promotions, where the temptation is to rely on a well-established track record in the technical domain. Technical track records are not proxies for people management capability. They need to be assessed separately and deliberately.

Protecting Your Teams and Your Technical Experts

Beyond protecting the teams these candidates would manage, pre-hire leadership testing also protects the technical experts themselves. Placing a high-performing specialist in a management role they're not suited for often destroys their job satisfaction, damages their confidence, and results in the loss of a technical contributor the organisation could genuinely not afford to lose in that capacity.

Ref Hub's platform is designed to help organisations mitigate hiring risks at exactly these inflection points — providing structured, evidence-based leadership assessment data before decisions are made that are difficult to reverse without significant collateral damage.

Conclusion

Technical excellence is valuable. People management capability is different. The most effective organisations recognise this distinction and build leadership pathways that don't require exceptional technical contributors to become managers in order to progress. When the management path is the only path, assessing for leadership readiness before making the move is not optional — it's essential.