Chief of Staff Case Interview: A 90-Minute Assessment for Strategic Operators
A Chief of Staff interview creates an unusual assessment problem. The role can involve strategy, executive decision support, cross-functional execution, sensitive communication and operating cadence — yet a conventional interview often rewards polished storytelling more than the work itself.
A short, structured case can reveal how a candidate frames ambiguity, separates evidence from assumption, chooses priorities and communicates a decision. It should not become an endurance test, unpaid consulting project or imitation of the CEO's personal style.
This guide offers a 90-minute work-sample assessment for hiring teams and a preparation framework for candidates. It is an MTF-designed decision aid, not a validated psychometric instrument or universal hiring standard.
What the case should measure
The assessment should focus on six capabilities that are close to the work:
| Capability | Observable question | Weak signal | Strong signal |
|---|---|---|---|
| Problem framing | Did the candidate define the decision, time horizon and success condition? | Repeats the prompt | Converts ambiguity into a decision statement and boundaries |
| Evidence discipline | Did the candidate distinguish facts, estimates and missing information? | Treats every number as certain | Labels assumptions and identifies the next evidence needed |
| Prioritisation | Did the candidate make trade-offs? | Produces a long task list | Selects a few actions using explicit criteria |
| Executive communication | Is the recommendation usable by a time-constrained leader? | Gives a chronological analysis dump | Leads with the decision, rationale, risks and asks |
| Operating design | Can the recommendation become owned work? | Says “align stakeholders” | Names owners, cadence, dependencies and escalation triggers |
| Judgment and trust | Does the candidate handle uncertainty and sensitive implications responsibly? | Overstates certainty or assigns blame | Surfaces risk without theatre and protects appropriate boundaries |
The purpose is not to find a candidate who already knows the company's private context. It is to observe the quality of their reasoning under a fair, bounded brief.
The 90-minute case format
Candidate brief: the situation
Use a fictional or sufficiently generalized business scenario. For example:
A subscription software company has missed its growth plan for two quarters. Product, sales and customer-success leaders disagree about the primary cause. The CEO wants a decision within two weeks on whether to change pricing, narrow the target segment or invest in retention. You receive a short data pack and notes from four stakeholders.
Ask the candidate to produce:
- a one-page executive decision memo;
- a 30-day operating plan;
- three questions they would answer before the final decision.
Suggested time allocation
| Activity | Minutes | Output |
|---|---|---|
| Read and frame | 15 | Decision statement, constraints and evidence map |
| Analyse | 25 | Main signals, contradictions and assumptions |
| Decide | 15 | Recommendation and alternatives rejected |
| Operationalise | 20 | Owners, milestones, cadence and risk triggers |
| Write and review | 15 | One-page memo plus 30-day plan |
| Total | 90 | Bounded work sample |
The candidate should receive the evaluation dimensions in advance. Hidden criteria create noise rather than realism.
Build a balanced case packet
A useful packet is small enough to understand in the allotted time and rich enough to create a real trade-off. Include:
- a one-page company and decision context;
- five to eight relevant metrics;
- short, conflicting stakeholder statements;
- one constraint such as cash, deadline or customer commitment;
- one deliberate information gap;
- clear deliverables and permitted tools.
Do not include confidential customer data, current employee performance issues or a live project that the company intends to use without hiring the candidate. The case should test reasoning, not extract free work.
A 100-point scorecard
Score the written output before the debrief to reduce halo effects.
| Dimension | Weight | Evidence expected |
|---|---|---|
| Decision framing | 15 | Clear decision, scope, deadline and success metric |
| Analysis and evidence | 20 | Correct use of data, contradictions and uncertainty |
| Prioritisation and trade-offs | 20 | Coherent recommendation and explicit alternatives |
| Operating plan | 20 | Owners, sequence, cadence, dependencies and triggers |
| Executive communication | 15 | Concise memo with the decision first |
| Judgment and integrity | 10 | Responsible handling of gaps, people and sensitive risk |
| Total | 100 |
Use behavioural anchors rather than intuition:
- 0-1: missing or materially unsafe;
- 2: partial, generic or weakly supported;
- 3: credible and role-relevant;
- 4: unusually clear, evidence-led and operationally useful.
For a 20-point dimension, multiply the 0-4 rating by five. Require evaluators to cite one observed strength and one uncertainty for each score.
The debrief: test adaptability, not defensiveness
After scoring the initial submission, run a 30-minute discussion. Introduce one new fact — for example, churn is concentrated in a previously profitable segment — and ask:
- What changes in your recommendation?
- What remains valid?
- Which stakeholder should be involved next, and why?
- What would you communicate to the CEO today?
Changing a view in response to material evidence is a positive signal. Uncritically abandoning the full plan is not. The interviewer is looking for calibrated adaptation.
A worked mini-case
Assume the packet shows:
- new bookings at 82% of plan;
- gross revenue retention falling from 91% to 86%;
- customer-acquisition cost up 18%;
- one segment producing 48% of support volume but 22% of revenue;
- product research suggesting a new feature, but no quantified willingness to pay.
A weak response chooses “build the feature” because it appears in stakeholder interviews. A stronger response separates three questions:
- Economics: Is the low-value segment creating a structurally unattractive service burden?
- Retention: Which reasons explain the five-point retention decline, and are they controllable?
- Growth: Is higher acquisition cost a channel problem, a conversion problem or a weak value proposition?
A credible 30-day plan might assign finance and customer success to segment economics, product and research to test willingness to pay, and revenue operations to diagnose acquisition efficiency. The CEO receives a weekly decision log and two predetermined escalation triggers. The recommendation is useful because it turns ambiguity into sequenced evidence rather than pretending the first packet resolves the strategy.
Candidate preparation: the FRAME method
Candidates can use the same discipline without memorising a “correct” answer.
F — Frame the decision
Write one sentence: “The executive needs to decide X by Y in order to achieve Z.” State what the case does not allow you to conclude.
R — Read for conflict
Mark facts, stakeholder claims, assumptions and missing evidence separately. Contradictions are often the center of the case.
A — Analyse alternatives
Compare at least two credible choices. Define decision criteria before selecting the recommendation.
M — Make the work executable
Translate the recommendation into owners, first milestones, cadence and escalation conditions.
E — Express the decision first
The first paragraph should state the recommendation, principal evidence, greatest risk and immediate ask. Supporting detail follows.
Hiring-team safeguards
Before using the assessment:
- provide the same core prompt, time and scoring dimensions to comparable candidates;
- offer reasonable accommodations and an accessible format;
- confirm whether AI tools are permitted and apply the rule consistently;
- avoid criteria unrelated to the essential role;
- use multiple evidence sources rather than one case score;
- document conflicts of interest and evaluator reasoning;
- delete or retain submissions under a defined candidate-data policy.
Local employment, disability and privacy rules vary. Hiring teams should obtain appropriate professional advice for their jurisdiction.
Practical conclusion
A Chief of Staff case interview should test whether a candidate can improve an executive decision and turn it into coordinated action. A bounded 90-minute work sample, transparent scorecard and evidence-changing debrief create a stronger signal than an ambiguous take-home task.
For a deeper view of the role, see MTF Institute's Chief of Staff role guide and Chief of Staff operating cadence.
MTF Institute's Executive Certificate in Chief of Staff develops strategic execution, CEO partnership, influence and case-based application. It is a professional certificate program, not an academic degree.