ShopTalk 703: Ujjwal Sharma and TC39
Feb 23, 2026
Ujjwal Sharma, a developer advocate and TC39 chair working on language features like Temporal and web i18n. He explains how the standards group makes decisions, trade-offs between engine costs and developer needs, and how features like Temporal, signals, the pipeline operator, and types-as-comments evolve and get implemented. He also outlines how to propose changes and get involved.
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Make Proposals Clearly Better Than Existing Patterns
- To propose a language change, create a clear repo/proposal and demonstrate utility and uniqueness versus existing APIs.
- Chris's playful querySelector-sum example shows TC39 expects concrete justification beyond minor ergonomics.
Post ES6 Conservatism And The TC39 Budget
- The pace of JavaScript additions slowed after ES6; TC39 now operates with a 'budget' so committees must be conservative.
- Ujjwal notes this is intentional to avoid unbounded language growth and complexity.
Temporal Origin Story From Moment Maintainers
- Temporal began as a community effort to replace the broken Date object and was championed by Moment.js maintainers.
- Ujjwal calls Temporal the single largest addition to the language, reworking timestamps, time zones and calendars.