Worked on the apache/calcite repository to address a bug in the handling of numeric range endpoints during JSON serialization and deserialization. Focused on improving the RelJson component, the work involved updating deserialization logic to correctly interpret Double and Decimal types, ensuring accurate round-tripping of numeric ranges. This was achieved by introducing new methods and overloads that provide explicit type information when parsing range endpoints from JSON. The solution enhanced the reliability and correctness of Calcite’s data type handling, particularly for numeric values. Java was used throughout, with an emphasis on robust unit testing and careful management of data types.