EX Squared LATAM logo
EX Squared LATAM

Multishore & tech staff augmentation experts! Building solutions for leading brands #ImagineBuildEvolve 🔭

Senior FullStack Developer, React, Node, AI

Frontend EngineerSoftware EngineerContractRemoteSeniorTeam 501-1,000Since 2000H1B No SponsorCompany SiteLinkedIn

Location

Brazil

Posted

4 days ago

Salary

0

Seniority

Senior

Bachelor Degree5 yrs expEnglishApolloGraphQLJavaScriptNode.jsReact

Job Description

Senior FullStack Developer, React, Node, AI

EX Squared LATAM

• Use modern tools and frameworks (REACT and Node.js) to architect and develop applications from the ground up • Build and maintain automated evaluation pipelines (evals) for agent and skill outputs • Define strict input/output contracts for MCP tools and agent skills using typed schemas • Own the prompt engineering lifecycle for assigned tools and skills • Contribute to the team's MCP tooling catalog

Job Requirements

  • 5+ years of working knowledge with modern frameworks and languages (REACT & NodeJS)
  • Familiarity with OAuth2/OIDC, API key management, and access audit trail patterns
  • Experience with SSR applications.
  • Experience with GraphQL and Apollo.
  • Experience building or integrating MCP-compatible REST/GraphQL APIs; familiarity with tool interface contracts, versioning, and consumer documentation.
  • Familiarity with SLO definition and basic observability practices (logs, metrics, distributed traces) for production API services.
  • Hands-on experience with LLM structured output patterns: function/tool calling
  • Familiarity with LLM evaluation approaches: building golden test sets, LLM-as-judge pipelines, and prompt regression testing; ability to quantify output quality with measurable metrics rather than vibes.
  • Experience building agentic workflows — multi-step tool chains, state machine-based agents, or orchestration frameworks (LangGraph, LangChain, AutoGen, or custom) — with an emphasis on deterministic routing and graceful failure handling

Benefits

  • Competitive compensation in USD
  • Access to learning platforms and professional development opportunities
  • Flexible work environment
  • Collaborative and multicultural teams

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