I went IoT edge device to MQTT broker, then a stream processor into a time-series store, with a websocket layer on top for the dashboard.
Start by clarifying requirements (scale, latency, accuracy, vehicle connectivity) and then walk through the end-to-end pipeline: data collection on the vehicle, transmission, ingestion, storage, and real-time serving. Emphasize trade-offs at each stage and how you would handle failures, scale, and data consistency.
Pro tip: Show awareness of the unique constraints of automotive systems: intermittent connectivity, safety-critical data, and the need for both real-time and batch processing. Mention how you would handle data loss during transmission and ensure idempotency in ingestion.
Ask about fleet size, update frequency, latency requirements, data accuracy, and vehicle connectivity. Understand what 'real-time' means (e.g., sub-second vs. seconds) and the consumers of the data.
Discuss sensors (GPS, OBD-II, CAN bus) and how to aggregate speed data. Consider edge processing to filter, compress, and buffer data during connectivity loss.
Choose protocols (MQTT, HTTPS, gRPC) based on reliability and overhead. Design an ingestion layer that handles high throughput, is scalable, and ensures exactly-once or at-least-once processing with idempotency.
Use a time-series database (e.g., InfluxDB, TimescaleDB) for real-time queries and a data lake (e.g., S3) for batch analytics. Consider stream processing (e.g., Kafka Streams, Flink) for real-time aggregations and alerts.
Expose data via WebSockets, Server-Sent Events, or gRPC streaming for real-time consumers. Provide REST APIs for historical queries. Discuss caching, rate limiting, and authentication.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Clarify the scope and constraints first, then propose a layered architecture that combines a secure command-and-control channel with an on-vehicle enforcement mechanism. Discuss trade-offs around safety, security, and fail-safe behavior, and outline how you would test and deploy it incrementally.
Pro tip: Emphasize fail-safe design: the kill switch should default to allowing critical safety functions while blocking only data egress, and include a hardware root of trust to prevent tampering. Also mention the need for an audit trail and remote attestation to prove the vehicle's state.
Ask questions to understand what 'sending data outside the system' means, which data channels are in scope, and what safety and regulatory constraints apply. Identify the acceptable latency, reliability, and security requirements.
Propose a secure, authenticated channel (e.g., using mutual TLS, signed commands) to deliver the kill switch command to a specific vehicle. Ensure the command is idempotent and can be verified by the vehicle.
Describe a mechanism at the network layer (e.g., firewall rules, VPN kill switch) or application layer (e.g., disabling telematics unit) that blocks outbound data. Use a hardware root of trust to prevent bypass.
Ensure the kill switch does not interfere with safety-critical functions (e.g., emergency calls, OTA safety updates). Define fallback behavior if the command cannot be delivered or if the vehicle is offline.
Outline a phased rollout with canary testing, remote attestation to confirm the switch is active, and logging for audit. Discuss how to handle false positives and recovery.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.