Backend Engineer (Nest.js/TypeScript) - Multi-Tenant Policy Gateway

The Opportunity

You'll be the engineer who builds a multi-tenant policy gateway for a US insurance carrier transforming its platform business. This service will connect a modern claims platform with N external policy systems, resolving tenant-specific requests, mapping policies through a canonical model, and ensuring strict data isolation. You'll work in a small pod with a tech lead and directly with the client’s staff engineer, engineering manager, and claims domain expert, integrating into their existing AWS-based codebase.

The environment is fast-paced, and you’ll propose, decide, and deliver without waiting for design tickets. Expect to study the client’s existing single-tenant precedent and internal conventions before writing your own code.

What you'll be doing

You’ll design and build a greenfield Nest.js/TypeScript service that authenticates incoming webhooks, resolves tenant-specific requests, fetches policies (via live API calls or daily file extracts), maps them through a canonical policy model, and returns them in the claims platform’s schema. Key tasks include:

• Defining the canonical policy model and driving the first partner’s field-mapping through business review
• Building observability (structured logs, metrics, Grafana dashboards, alerts) and an onboarding runbook for tenant #2
• Ensuring security review and launch readiness, including writing isolation negative tests and running failure-mode drills
• Collaborating directly with client engineers and domain experts across time zones, primarily asynchronously

Your Responsibilities

• Design and build the gateway service on the client’s Nest.js-based internal framework and AWS, proposing infrastructure changes via Terraform PRs
• Implement webhook contracts with HMAC authentication, IP allowlisting, ISO-8601 date handling, and policy-version-at-date-of-loss logic
• Build a tenant router and registry with composite resolution and well-defined failure behavior
• Develop a source adapter framework for per-source authentication, timeouts, retries with backoff, and circuit breaking
• Create a batch path for SFTP landing zones, file validation, quarantine, and idempotent loads into a PostgreSQL policy store with snapshot retention and freshness monitoring
• Define the canonical policy model and mapper, reviewing the first partner’s mapping tables with the client’s claims expert
• Ship per-tenant observability (structured logs, metrics, Grafana dashboards, alerts) and an onboarding runbook
• Write isolation negative tests, run failure-mode drills, and support the client’s security review
• Collaborate directly with client engineers and domain experts across time zones, largely asynchronously

Requirements

• 5+ years of backend engineering experience with strong, recent TypeScript in production; experience with Nest.js or a comparable DI-based Node framework
• Experience building integration services or API gateways, including webhooks, signature-based authentication, retries, idempotency, circuit breakers, and third-party API adapters
• Proficiency with PostgreSQL and relational data modeling, including schema design and migrations
• Experience with multi-tenant systems or domains requiring strict data isolation, with an emphasis on testing isolation explicitly
• Hands-on experience with AWS (ECS/EKS or Lambda, SQS, S3, IAM, Secrets Manager or Vault) and the ability to read and propose Terraform, even if others apply it
• An AI-native approach to work, leveraging tools like Claude Code and Codex as core delivery aids while still reviewing every line of shipped code
• Self-directed with the ability to scope ambiguous requests, write concise design notes, ask the right questions early, and deliver without heavy oversight
• Fluent English and clear, proactive communication with both technical and non-technical stakeholders

Nice to Have

• Insurance domain exposure, including policy administration systems, claims, FNOL, coverages, deductibles, and MGA/carrier structures
• Experience with batch or file-based integrations (SFTP ingestion, schema validation, quarantine patterns) or data-mapping-heavy work
• Regulated-data experience, such as PII/PHI handling, HIPAA, or SOC 2 controls, and audit logging
• Experience with Grafana or OpenTelemetry-style observability
• Prior consulting or client-facing delivery experience

Benefits

• Unrestricted AI Stack & Premium Gear: Fully paid licenses for tools like Cursor and Claude Pro
• Total Autonomy (Remote-First): No unnecessary meetings, no Jira bureaucracy, no micromanagement. Own your workflow and focus on shipping systems in production
• Direct Impact: Work closely with the CEO, CTO, and VPs, as well as client leadership
• Frontier Engineering Culture: Collaborate with elite engineers building systems that drive real business decisions, backed by continuous growth and a strong knowledge-sharing culture