spotlight APL function, see spotlight.
Spotlight is particularly useful for:
- Root cause analysis: Quickly identify why certain traces are slower, errors are occurring, or performance is degraded.
 - Anomaly investigation: Understand what makes problematic events different from normal baseline behavior.
 - Pattern discovery: Spot trends and correlations in your data that might not be immediately obvious.
 
Axiom’s Spotlight feature in action
How Spotlight works
Spotlight compares two sets of events:- Comparison set: The events you select by highlighting a region on a chart.
 - Baseline set: All other events that contributed to the chart.
 
- Calculates the differences between the two sets and ranks them by significance.
 - Displays the most interesting differences using visualizations that adapt to your data types.
 - Gives an AI-generated summary that helps you interpret the visualizations.
 
Use Spotlight
Start Spotlight analysis
- In the Query tab, create a query that produces a heatmap or time series chart.
 - On the chart, click and drag to select the region you want to investigate.
 - In the selection tooltip, click Run Spotlight.
 
Interpret results
Spotlight displays results using two types of visualization, depending on your data:- 
Bar charts for categorical fields (strings, booleans)
- Compares the proportion of events that have a given value for selected and baseline events.
 - Useful for understanding differences in status codes, service names, or boolean flags.
 

Example barchart
 - 
Boxplots for numeric fields (integers, floats, timespans) with many distinct values
- Shows the range of values in both comparison and baseline sets.
 - Identifies the minimum, P25, P75, and maximum values.
 - Useful for understanding differences in response times or other numeric quantities.
 

Example boxplot
 
Dig deeper
To dig deeper, iteratively refine your Spotlight analysis or jump to a view of matching events.- Filter and re-run: Right-click specific values in the results and select Re-run spotlight to filter your data and run Spotlight again with a more focused scope.
 - Show events: Rick-click specific values in the results and select Show events to filter your data and see matching events.
 
Spotlight limitations
- Custom attributes: Currently, custom attributes in OTel spans aren’t included in the Spotlight results. Axiom will soon support custom attributes in Spotlight.
 - Complex queries: Spotlight works well for queries with maximum one aggregation step. Complex queries with multiple aggregations aren’t supported.
 
Example workflows
Investigate slow traces
- 
Create a heatmap of trace durations. For example, run the following query:
Run in Playground
 - Select the region showing the slowest traces.
 - Run Spotlight to see if slow traces are associated with specific endpoints, regions, or user segments.
 
Understand error spikes
- 
Build a time series of error-level logs. For example, run the following query:
Run in Playground
 - Select the time period where errors spiked.
 - Run Spotlight to identify if there’s anything different about the selected errors.