About The RoleWe are building a multi-tenant, hardware-agnostic IoT platform from the ground up. We need a senior engineer who can design the system architecture in the morning and write production backend code in the afternoon. This is not an architecture-only role and not a coding-only role — it is both, simultaneously, in a fast-moving early-stage environment. You will also own cloud infrastructure as interim DevOps until we scale.The Ideal CandidateYou have built IoT backend platforms before — not just used them. You understand the hard problems: device auth at scale, MQTT broker design, time-series ingestion performance, multi-tenant data isolation, and real-time delivery to web clients. You are comfortable making architectural decisions autonomously, documenting them clearly, and standing by them. You work remotely with discipline — you flag risks before they become problems.Key ResponsibilitiesPlatform ArchitectureDesign the full end-to-end IoT platform architecture: device connectivity layer → MQTT/protocol ingestion → stream processing → time-series storage → REST/GraphQL API layer → real-time WebSocket deliveryDefine the multi-tenant data model: strict data isolation between customers, tenant-scoped API tokens, row-level securityDesign the device lifecycle system: provisioning, X.509/JWT authentication, device registry, status tracking, decommissioningArchitect the protocol abstraction layer so MQTT, Modbus, OPC-UA, CoAP, and HTTP devices all normalise to the same internal data modelDesign a configurable rule engine: event-condition-action rules for alerts, automations, and integrations — no code required from customersPlan OTA firmware update management: secure delivery, versioning, rollback, fleet orchestrationWrite Architecture Decision Records (ADRs) for every major technical choice — nothing undocumentedDesign the scaling path from 100 devices (pilot) to 500,000+ (production) without structural reworkBackend DevelopmentBuild core platform services from scratch: device management, telemetry ingestion, rule engine, notification/alerting, OTA update, multi-tenant API gatewayDevelop REST and GraphQL APIs with full OpenAPI specification — version-controlled from Day 1Implement WebSocket and SSE endpoints for real-time telemetry delivery to web and mobile clientsBuild device command-and-control with acknowledgement, retry logic, and timeout handlingImplement device shadow service: last-known state of every device accessible even when offlineWrite unit, integration, and load tests — no service reaches staging without test coverageOwn service reliability: SLO definitions, alerting runbooks, on-call incident responseCloud Infrastructure (Interim)Provision and manage all AWS environments (dev, staging, production) using Terraform — no click-opsConfigure AWS IoT Core: MQTT endpoint, topic namespace, rules engine, certificate managementSet up CI/CD pipelines via GitHub Actions for all backend servicesConfigure CloudWatch monitoring, log aggregation, and automated health alertsManage IAM for all team members — least-privilege access, no shared credentialsHand off infrastructure fully documented when a DevOps engineer joins in Phase 2Requirements7-12 years software or systems engineering; minimum 4 years specifically building IoT platform backends or connected product infrastructureExpert-level, hands-on experience with AWS IoT Core or Azure IoT Hub — production deployments, not tutorials ⚑ NON-NEGOTIABLEExpert MQTT knowledge: v3.1 and v5.0, topic hierarchy design, QoS levels, retained messages, Last Will & Testament, broker sizing and clustering ⚑ NON-NEGOTIABLEProficiency in Python and Node.js/TypeScript for production backend services — Go is a strong advantageHands-on experience with a time-series database: InfluxDB, TimescaleDB, or AWS TimestreamTerraform or AWS CloudFormation — you provision cloud infrastructure programmatically, not through the consoleMulti-tenant SaaS backend architecture: data isolation patterns, tenant-scoped access control, shared infrastructure designSecurity fundamentals applied in practice: TLS/mTLS, X.509 certificates, OAuth 2.0, JWT, secrets management (Vault or AWS Secrets Manager)Message broker or streaming experience: Kafka, RabbitMQ, AWS Kinesis, or AWS IoT Rules EngineProven ability to work autonomously at a senior level — makes decisions, documents rationale, flags risks without needing to be prompted ⚑ REMOTE DISCIPLINENice to HaveIndustrial protocol knowledge: Modbus TCP/RTU, OPC-UA, BACnet — even as a consumer or integratorEMQX, HiveMQ, or VerneMQ broker deployment and production operationEdge computing runtimes: AWS Greengrass v2, Azure IoT Edge, or BalenaDigital twin frameworks: AWS IoT TwinMaker, Azure Digital TwinsContainer orchestration: Kubernetes, ECS, or equivalent for future Phase 2 migrationOpen-source IoT contributions or published technical writing on platform architectureSkills At a GlanceArchitecture: IoT platform end-to-end design Multi-tenant SaaS patterns Device lifecycle management Protocol abstraction Rule engine design Horizontal scaling strategyBackend: Python / Node.js / TypeScript / Go REST + GraphQL API design WebSocket / SSE real-time delivery MQTT broker configuration Time-series DB (InfluxDB / Timestream) PostgreSQL or equivalent RDBMSCloud & DevOps: AWS IoT Core / Azure IoT Hub Terraform / CloudFormation GitHub Actions CI/CD Docker containers CloudWatch monitoring IAM and security policy managementSecurity: TLS / mTLS configuration X.509 certificate management OAuth 2.0 / JWT implementation Secrets management Device authentication at scale