How would you improve reliability and latency for Logistics Platform

Problem Statement Description

Product context: DoorDash is a local commerce and delivery platform; its products include restaurant delivery, DashPass, grocery and retail delivery, merchant tools, and dasher tools.

DoorDash’s Logistics Platform powers real-time delivery decisions across the marketplace, including order dispatch, Dasher assignment, route updates, batching, ETA calculations, and status transitions. In this interview, you are asked to evaluate how the platform should be improved for reliability and latency, with particular attention to how delays or failures affect Dashers, merchants, consumers, and marketplace efficiency.

Focus on the end-to-end technical product experience behind a delivery: a consumer places an order, a merchant prepares it, the platform identifies and notifies an eligible Dasher, the Dasher accepts, navigates to pickup and dropoff, and the system continuously updates state across apps and internal services. Reliability and latency issues may show up as delayed offers, stale order state, inaccurate ETAs, missed pickups, duplicate assignments, Dasher idle time, or degraded marketplace trust.

You are not expected to design low-level infrastructure in detail, but you should be able to frame the product and technical requirements, identify critical dependencies, reason about APIs and data flows, define reliability and latency goals, and discuss trade-offs between speed, accuracy, cost, fairness, and operational complexity.

The experience should consider:

- Critical user workflows for Dashers, merchants, consumers, and support teams during order assignment and delivery execution

- System boundaries and dependencies across dispatch, notifications, location updates, routing, payments, merchant systems, and mobile clients

- Latency-sensitive moments such as order offer generation, Dasher acceptance, pickup readiness, route recalculation, and ETA refreshes

- Reliability expectations, failure modes, fallback behavior, retries, idempotency, and graceful degradation during traffic spikes or service outages

- Data freshness, event ordering, API contracts, state consistency, and how stale or missing signals affect marketplace decisions

- Observability needs, including SLIs/SLOs, alerting, tracing, dashboards, incident review, and cohort-level monitoring by region, order type, and Dasher app version

- Privacy, security, and trust considerations around location data, identity, delivery status, and sensitive marketplace operations

- Rollout strategy, experimentation, migration risk, rollback criteria, and communication with operations and support teams

The goal is to demonstrate how you would approach reliability and latency as a Technical PM: translating marketplace pain points into technical requirements, prioritizing the highest-impact workflows, aligning engineering and operations teams, and defining measurable improvements that make DoorDash deliveries faster, more predictable, and more resilient.