Senior Backend Engineer (TypeScript / Nest.js / AWS)

Quick Facts

• Focus: Build a multi-tenant policy gateway for a claims platform integration
• Stack: Nest.js / TypeScript on AWS
• Context: US insurance carrier; policy systems integration for specialist insurers (MGAs)
• Start: October 2026

Description

Build a greenfield Nest.js / TypeScript service that sits between the claims platform and external policy systems. It authenticates incoming webhooks, resolves the tenant for each request, fetches the correct policy (live API call or from a policy store fed by daily file extracts), maps it through a canonical policy model, and returns it in the claims platform schema with strict hard data isolation between tenants.

The spec is a PRD, so you are expected to propose, decide, and deliver.

Responsibilities

• Design and build the gateway service on the client’s Nest.js-based internal framework and AWS; propose infrastructure changes via Terraform PRs
• Implement the webhook contract including HMAC authentication (secrets in Vault), IP allowlisting, ISO-8601 date handling, and policy-version-at-date-of-loss selection
• Build the tenant router and registry with composite resolution and well-defined failure behavior
• Build a source adapter framework with per-source auth, timeouts, retries with backoff, and circuit breaking
• Build the batch path: SFTP landing zones per tenant, file validation and quarantine, idempotent loads into a PostgreSQL policy store with snapshot retention and freshness monitoring
• Define the canonical policy model and the shared canonical-to-target mapper; drive the first partner’s field mapping through business review
• Ship per-tenant observability (structured logs, metrics, Grafana dashboards, freshness and error-rate alerts) and an onboarding runbook for tenant #2
• Write isolation negative tests as a release gate, run failure-mode drills, perform end-to-end walkthroughs in the client’s sandbox, and support security review
• Collaborate with client engineers and domain experts across time zones, largely async; limited PT timezone availability required

Requirements

• 5+ years backend engineering with strong, recent TypeScript in production; Nest.js or a comparable DI-based Node framework
• Experience building integration services or API gateways: webhooks, signature-based auth, retries, idempotency, circuit breakers, third-party API adapters
• PostgreSQL and relational data modeling; design schemas and write migrations
• Experience with multi-tenant systems or domains where data isolation is a hard requirement; instinct to test isolation explicitly
• Hands-on AWS (ECS/EKS or Lambda, SQS, S3, IAM, Secrets Manager or Vault); able to read and propose Terraform
• AI-native way of working using tools like Claude Code and Codex as a core part of delivery
• Self-directed: scope ambiguous requests, write short design notes, ask the right questions early, and deliver without heavy oversight
• Fluent English and clear, proactive communication with technical and non-technical stakeholders
• Availability in PT timezone at most once a week

Benefits

• Unrestricted AI Stack & premium gear (fully paid Cursor, Claude Pro, etc.)
• Remote-first autonomy: no filler meetings, no Jira bloat, no micromanagement
• Direct impact with leadership and the CEO/CTO/VPs
• Frontier engineering culture focused on shipped production systems and continuous growth