REPOSITORY CODING · HARD
Captured measurements change after a calibration rollout
A lab captures device readings before a calibration rollout. Processing those readings later produces different values, and Fahrenheit devices disagree with Celsius devices. Trace capture, calibration activation and unit conversion. Restore reproducible results without blocking new calibrations.
Data EngineerMeasurement calibration lab
Work through a real codebase.
Choose an environment, investigate the existing implementation and use the tests to check your change. Sign in to open a workspace; execution and Ono usage follow your plan’s allowances.
Task requirements and environments
Django · 90 minute session
- Devices, calibrations and batches belong to a tenant. Identifiers may be reused in different tenants. Device units are C or F.
- A calibration has positive gain, an offset and an inclusive lower/upper range. Its author cannot approve it. Activation requires approval, the same device, and the current device revision.
- Capture freezes the device revision, unit and active calibration. Later activations cannot change an existing batch. Every sample occurrence is retained, even if IDs repeat.
- Convert raw Fahrenheit to Celsius before applying gain and offset. Round corrected values to four decimal places. Reject values outside the inclusive calibrated range.
- Summary count includes all samples. Accepted and rejected counts reflect quality. Mean uses only accepted values, rounded to four decimals; it is null when none qualify.
- Processing and export are repeatable without duplicate audit entries. Export requires processed data and freezes the report. Discarded batches cannot be processed or exported; exported batches cannot be discarded.
- Every state change and its audit entry commit together. failAudit simulates an audit failure and must roll back the entire command. A subsequent successful retry must behave as if the failed command never happened.
Flask · 90 minute session
- Devices, calibrations and batches belong to a tenant. Identifiers may be reused in different tenants. Device units are C or F.
- A calibration has positive gain, an offset and an inclusive lower/upper range. Its author cannot approve it. Activation requires approval, the same device, and the current device revision.
- Capture freezes the device revision, unit and active calibration. Later activations cannot change an existing batch. Every sample occurrence is retained, even if IDs repeat.
- Convert raw Fahrenheit to Celsius before applying gain and offset. Round corrected values to four decimal places. Reject values outside the inclusive calibrated range.
- Summary count includes all samples. Accepted and rejected counts reflect quality. Mean uses only accepted values, rounded to four decimals; it is null when none qualify.
- Processing and export are repeatable without duplicate audit entries. Export requires processed data and freezes the report. Discarded batches cannot be processed or exported; exported batches cannot be discarded.