Product Sense · medium
How do you design a KPI dashboard for an executive who has 30 seconds?
Asked in BI Developer interviews.
Short answer
Lead with the few metrics tied to their goals, each with context (target, trend, and variance) not a bare number. One screen, no scrolling, an obvious good/bad direction. Detail lives one click down for whoever needs it. The 30-second read is are we on track and where is the problem.
How to answer it
The constraint drives everything
Thirty seconds means the reader answers one question: is anything wrong, and if so where. Not what happened, not why. Design for the glance, and put the explanation one click below.
The layout
Top 3 to 5 headline numbers, each with a comparison and a
direction. A number alone is unreadable: revenue of
2.1m means nothing without last month beside it
Middle trend for each headline, small and simple. Sparklines
beat full charts here
Below the fold the breakdowns, for when something looks wrong
Always visible "data as of", so nobody acts on stale numbersWhat makes it readable in 30 seconds
- Comparison, always. Against target, against last period, against last year. Choose one and use it consistently.
- Direction and judgement, not just change. Up 4% is a fact; up 4% against a 2% target is information.
- Color meaning one thing. Green is good, red is bad, and nothing else is colored. A rainbow palette destroys the glance.
- Consistent units and rounding. 2.1m, not 2,134,981.
- Almost no text. If it needs a paragraph, it is not a glance dashboard.
What to leave out
Anything they cannot act on. Vanity metrics that only go up, breakdowns that belong to a team lead rather than an executive, and any chart that exists because someone once asked for it. Every extra element costs a share of the thirty seconds.
Key points
- One question: is anything wrong, and where.
- Three to five headline numbers, each with a comparison.
- Color carries meaning, so use it only for good and bad.
- Detail lives below the fold or one click away, not on the front.
- Show data freshness prominently; a stale number acted on is worse than no number.
FAQ
- How many metrics is too many? Past about seven, the glance fails. Five is a good ceiling.
- Should it have filters? Ideally none at the top level. Filters are for the layer beneath.
- What if different executives want different things? Either one dashboard per role, or a shared top with role-specific sections underneath.
The 30-second answer
At thirty seconds they can only answer one question: is anything wrong, and where. So I would design for that and put the explanation one click below.
Three to five headline numbers at the top, each with a comparison against target or last period, because a number on its own is unreadable. A small trend beside each. Everything else below the fold.
The details that make it work in a glance are color meaning exactly one thing, green good and red bad and nothing else colored, consistent rounding, almost no text, and a visible data-as-of timestamp. And I would leave out anything they cannot act on, because every extra element spends part of the thirty seconds.
In the interview
- What they are checking: that you design for the two questions, with targets and trends, and cut everything else.
- Common mistake: a "summary" page that is itself a wall of small charts.