Senior Frontend Engineer, Query Builder & Editor Core

Analysts using our product build audiences by stacking up nested filters, things like "country is US and (plan is Scale or seats over 10)", and they expect to undo and redo freely as they go. We're hiring a senior frontend engineer to own the engine behind that builder. It's pure TypeScript, and the React UI just renders and dispatches, so all the real logic is yours.

What you'll do:

• Build immutable operations on a nested AND/OR condition tree: add, remove, duplicate, move, group, validate, and serialize to a stable format
• Build undo and redo as a proper command history, with a bounded stack, coalescing of rapid edits, and a redo stack that clears once a new edit lands
• Make the judgment calls on how aggressively to coalesce edits and how to normalize groups
• Never mutate a caller's tree, and keep ids and time injected so behavior stays predictable

What we're looking for:

• Strong TypeScript and real comfort with immutable, recursive data structures
• Experience implementing undo/redo or a command pattern, plus validation
• Careful, well-typed code and good test habits

Nice to have:

Built a query or segment builder before, and comfortable with serialization and canonical forms