DevJobs

Senior Back End Engineer (API & Agentic AI)

Overview
Skills
  • TypeScript TypeScript
  • NestJS NestJS
  • Express.js Express.js
  • Integration tests
  • Validation
  • Unit tests
  • Testing
  • Service-to-service auth
  • RBAC
  • HTTP
  • Contract-driven development
  • Authorization
  • Authentication
  • API tests
  • API security
  • Fastify
  • AdonisJS
  • Koa
  • Effect
  • Observability tooling
  • OpenAPI
  • Cloud-native deployments
  • Swagger

What You’ll Do

Backend & Platform Architecture

  • Contribute to the design and implementation of a multi-service backend architecture
  • Design, build, and maintain robust, well-documented APIs for internal and external consumers
  • Help define backend standards that support both traditional SaaS workflows and AI-driven, agent-based execution
  • Collaborate on architectural decisions and provide technical guidance within the engineering team

Agentic AI Enablement

  • Design backend primitives and services that support agentic AI systems (e.g., task execution, state management, orchestration, tool invocation)
  • Build APIs and infrastructure that allow AI agents to safely interact with internal services, data, and external systems
  • Implement guardrails for agent execution, including authorization boundaries, auditability, rate limits, and failure handling
  • Partner with data science and ML engineers to productionize AI workflows in a reliable, observable, and secure way

Backend Best Practices & Reliability

  • Implement and improve backend best practices, including:
  • Authentication and authorization (token-based auth, RBAC, service-to-service auth)
  • Idempotency and safe retry mechanisms
  • Consistent error modeling and API contracts
  • Input validation and schema enforcement
  • API versioning and backward compatibility
  • Ensure backend services follow strong networking and security principles
  • Help establish and maintain observability standards (logging, metrics, tracing)
  • Write high-quality, well-tested TypeScript code

What We’re Looking For

  • 7+ years of professional software engineering experience, primarily focused on backend systems
  • Strong expertise in TypeScript for server-side development
  • Proven experience designing and implementing APIs for complex systems
  • Experience with Nest.js or another major TypeScript backend framework (e.g., AdonisJS, Express, Fastify, Koa)
  • Solid understanding of:
  • HTTP and networking fundamentals
  • API security and authentication/authorization patterns
  • Reliability concerns in distributed systems
  • Experience with:
  • API documentation (OpenAPI / Swagger)
  • Testing strategies (unit, integration, API tests)
  • Validation and contract-driven development
  • A pragmatic, ownership-oriented mindset with strong engineering judgment
  • Comfort working in systems that mix deterministic software with probabilistic AI components

Nice to Have

  • Experience participating in monolith-to-services or modularization efforts
  • Experience supporting external, customer-facing APIs
  • Experience designing systems that support AI agents, workflows, or automation platforms
  • Familiarity with LLM tooling concepts (tools/functions, agent loops, structured outputs)
  • Experience with Effect
  • Familiarity with healthcare, life sciences, or regulated environments
  • Experience with cloud-native deployments and production observability tooling

Why QuantHealth

  • Work on technically deep problems at the intersection of backend systems and AI in healthcare
  • Help shape both a scalable backend platform and the foundations of agentic AI capabilities
  • Collaborate with a thoughtful, high-caliber engineering team
  • Competitive compensation and opportunities for growth

QuantHealth