Designing a useful button_click event payload
Event instrumentation design.
Include identity, timestamp, and context plus properties like button id, screen, and state; govern with a naming convention.
A bare event name, or ad hoc field names per event.
WHAT THIS TESTS Whether you design instrumentation that is consistent, governed, and analytically rich, so questions you have not thought of yet can still be answered later.
A GOOD ANSWER COVERS Every event needs three pillars: identity, timing, and context. Identity means a stable user id when known and an anonymous or device id otherwise, so you can stitch pre- and post-login behavior. Timing means the client event timestamp and ideally a server received timestamp to detect clock skew and late delivery. The event itself should have a clear, convention-following name such as Button Clicked rather than a generic click. Then attach a typed properties object: which button via a stable button id plus a human-readable label, where it lives such as screen or route and component, the app version and platform, the session id, and any state that gives the click meaning like the item or cart value involved. Include super properties shared across events such as plan and device type so analysis can segment without extra joins.
COMMON WRONG ANSWERS Sending only the event name with no properties, which makes the data nearly useless. Putting variable detail into the event name, such as Button Clicked Checkout versus Button Clicked Save, instead of a button property, which explodes the event namespace. Inconsistent casing or ad hoc field names across teams. Forgetting identity or timestamps.
GOVERNANCE Maintain a tracking plan and naming convention using object-action style and consistent case, validate payloads against a schema, and avoid putting personally identifiable information into properties.
ONE CONCRETE EXAMPLE A checkout click emits the event Button Clicked with properties button_id checkout_submit, label Place Order, screen Cart, cart_value 49.99, currency USD, app_version 3.4.1, platform iOS, session_id, and user_id. This lets analysts later compute conversion by platform or by cart value without ever changing the instrumentation, because the meaningful detail lives in properties rather than in dozens of bespoke event names.
Interview question
Why is logging Button Clicked with a button_id property better than separate events like Checkout Clicked and Save Clicked?
- a.It removes the need for a user identifier on the event
- b.It reduces payload size since property values compress better
- c.It guarantees the data contains no personally identifiable information
- d.It keeps the event namespace clean and lets analysts segment without new eventsCorrect
Why? this is the answer
A shared event with a discriminating property avoids namespace explosion and enables flexible segmentation. The other options are unrelated; naming style does not affect compression, PII, or the need for identity.
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