UniqueHire Consulting LLC

Senior Frontend Engineer - Web UI / API Integration

New York, New York, USA · Senior · Contract

Sponsorship not specifiedDetected 55 days ago

JavaScriptTypeScriptReactReduxFull-Stack DevelopmentCode ReviewGitGraphQLRESTFigmaAgileLogisticsJest

About the role

You will work inside a mature micro frontend ecosystem where the architectural complexity is abstracted away by tooling, so your day-to-day focus is on delivering well-tested, resilient features that integrate against GraphQL and REST APIs.
Integrate against GraphQL and REST APIs, handling partial data, schema-level errors, transport errors, and the difference between retryable and terminal failures.
Aggregate data across multiple resources utilizing built-in Javascript features, and surface it through well-typed client state.

Implement features against atomic user stories, inside an SSR-first, independently deployable micro frontend module.
Own the server-state vs client-state boundary, TanStack Query for server state (caching, refetch, dedup, lifecycle), Redux for cross-module and derived UI state.
Can converse with backend engineers about contract design rather than just consuming what they hand over.
You will own your stories end to end, including their failure modes.

Strong React 18+ experience: hooks, suspense, concurrent rendering implications, component composition over inheritance.
Total type safety in TypeScript: discriminated unions, generics, mapped and conditional types, type narrowing.
Comfortable modeling API responses, error states, and domain entities as precise types, not just as interfaces with optional fields.
Redux (Redux Toolkit) for client and cross-module state, slices, selectors, memoization, normalized state shape.
Articulates clearly where the boundary sits between the two and does not put server responses in Redux by default.
REST integration with explicit handling of HTTP semantics (idempotency, status code classes, retry policy, timeouts).
Defensive integration: input validation, output validation against contract, and explicit failure modes for every external call.
Comfort merging, reducing, filtering, and shaping data from multiple sources before it reaches the UI layer.
React Testing Library as the default for component and integration tests, user-facing behavior, not implementation details.
Jest for unit tests, utilities, reducers, selectors, and the fragments RTL is not the right tool for.
Comfortable working towards 100% code coverage as a sustained standard, not a one-time push.
Parrot or equivalent for mocking the API boundary in tests.

Deliver features with 100% code coverage using Jest and React Testing Library, and know when each tool is the right choice.
Rejects PRs lacking error handling, type safety, or test coverage, including your own.

6+ Months with possibility of extension Financial services domain Role Summary We are looking for a Senior Frontend Engineer to join a domain-focused product team within a large financial services client.

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