What are the responsibilities and job description for the Backend Engineer_ AI Gateway position at Nexien Inc.?
Position Information
- Job Title: Backend Engineer _ AI Gateway
- Work Hours: 9-6 local time
- Work Location:
-700 Sylvan Ave Englewood Cliffs, NJ 07632 (through September 2026)
-6625 Excellence Way, Plano, TX 75023 (effective October 2026 onward
JD Details
We are building an AI Gateway — a high-performance, secure intermediary layer that routes, inspects, and governs all traffic between enterprise clients and LLM/AI service providers. This role requires deep expertise in network programming, async Python, and cloud infrastructure to design and operate a latency-sensitive, policy-driven gateway that handles massive concurrent streaming connections at scale.
What we are looking for
- Async Python & Network Programming (3 yrs) – Strong hands‑on experience with asyncio, aiohttp/anyio, low‑level TCP/UDP sockets, WebSocket & SSE servers, TLS handshake, connection‑pooling, keep‑alive, and zero‑copy buffering.
- Streaming & Large‑Payload Handling – Ability to manage chunked transfer, bidirectional streaming, back‑pressure and high‑throughput data paths for real‑time LLM inference.
- Protocol Knowledge – Working familiarity with HTTP/2 & HTTP/3 (multiplexing, HPACK), gRPC, and occasional custom protocol parsers.
- FastAPI‑Based Backend (3 yrs) – Design, develop and test production‑grade REST/Streaming APIs; pragmatic use of Pydantic, dependency injection and OpenAPI docs.
- Containerization & Kubernetes – Docker, AKS/EKS/GKE deployment experience; HPA/VPA scaling, rolling updates, and service‑mesh (e.g., Istio/Envoy) basics.
- Async Messaging & Event‑Driven Design – Production use of Redis Streams, RabbitMQ or Kafka for decoupled task queues, retries and back‑off logic.
- PostgreSQL & Vault – Advanced query tuning, partitioning, PgBouncer pooling, plus HashiCorp Vault (dynamic secrets, transit encryption) for key management.
- Cloud Networking & Security – L4/L7 load balancing, TLS termination, reverse‑proxy (NGINX/Envoy), mTLS between services, and automated cert lifecycle (ACME/Let’s Encrypt).
- IaC & CI/CD – Terraform modules for multi‑env infra, plus GitHub Actions/GitLab CI pipelines with container image scanning and canary/blue‑green deployments.
Work experience desired
- Enterprise Security Gateways – Integration with CASB/DLP/WSS or similar edge‑security platforms; centralized logging & audit trails.
- IAM & SSO – Configuring Azure AD/Entra ID, Okta, SAML 2.0 or OIDC SSO flows; managing Conditional Access & SCIM provisioning.
- AI/LLM Pipelines – Building prompt‑engineering workflows, PII anonymisation, and monitoring Azure OpenAI (or comparable) usage, rate limits & cost.
- API‑Gateway Operations – Custom webhook/REST integrations, circuit‑breaker patterns, rate‑limiting, auto‑retry and health‑checking.
- Observability & FinOps – End‑to‑end monitoring with Datadog, Prometheus/Grafana or Azure Monitor; proactive cost‑optimisation and 24/7 incident response (SLA/SLO).