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System Design questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master system design interviews.

What difficulty level is this interview question?

This is a hard difficulty System Design question, commonly asked during Onsite rounds at DoorDash.

What role is this question designed for?

This question is commonly asked for Software Engineer candidates at DoorDash during technical interviews.

Design cron scheduler and reward/review system

Quick Overview

This question evaluates system design competencies including distributed scheduling and workflow orchestration, multi-tenant isolation, scalability, reliability, operational observability, data modeling, and privacy/compliance for employee review and rewards.

System Design: Company-Wide Scheduler Platform and Employee Review & Rewards System

You are designing two platforms for a fast-growing, multi-tenant technology company. Address each part independently, but note any shared building blocks if relevant.

Part A — Company-Wide Scheduled Job Platform (Cron-like)

Design a horizontally scalable platform to run scheduled workflows across services.

Include:

Scheduling and execution
- Schedule management: crontab expressions, calendar/holiday exceptions, and time zones (DST-safe)
- Workflow DAGs and task dependencies
- Retries with exponential backoff and idempotency guarantees
- Backfills for missed/retroactive runs
- Concurrency control: global, per-tenant, per-workflow limits
- Access control and multi-tenant isolation
Reliability and operations
- Observability: logs, metrics, traces; failure alerting
- Horizontal scalability: sharding and stateless workers
- Storage schemas for schedules, DAGs, runs, leases/locks, and audit
- Coordinator/worker architecture: leader election, queues, heartbeats
- Disaster recovery and operational runbooks

Discuss trade-offs (e.g., at-least-once vs exactly-once), and provide concrete storage schemas and component interactions.

Part B — Employee Review & Rewards System

Design a system that supports performance reviews and employee rewards with strong privacy and compliance.

Include:

Core features
- Performance review cycles (self/manager/peer), calibration, and peer feedback
- Reward points/grants, redemption, policies, and approval workflows
- Privacy/visibility controls and audit trails
Architecture and integrations
- Service boundaries and data models
- Integrations with HRIS (org, titles, managers), SSO, and payroll/stock systems
- Abuse/fraud prevention, rate-limiting, and anomaly detection
Operations
- Observability, SLAs, and disaster recovery
- Data retention, legal holds, and regional data residency

Provide data schemas, state machines, and key workflows. Call out edge cases, safeguards, and scale assumptions.

Quick Overview

Part A — Company-Wide Scheduled Job Platform (Cron-like)

Design a horizontally scalable platform to run scheduled workflows across services.

Include:

Scheduling and execution

Schedule management: crontab expressions, calendar/holiday exceptions, and time zones (DST-safe)
Workflow DAGs and task dependencies
Retries with exponential backoff and idempotency guarantees
Backfills for missed/retroactive runs
Concurrency control: global, per-tenant, per-workflow limits
Access control and multi-tenant isolation

Reliability and operations

Observability: logs, metrics, traces; failure alerting
Horizontal scalability: sharding and stateless workers
Storage schemas for schedules, DAGs, runs, leases/locks, and audit
Coordinator/worker architecture: leader election, queues, heartbeats
Disaster recovery and operational runbooks

Discuss trade-offs (e.g., at-least-once vs exactly-once), and provide concrete storage schemas and component interactions.

Part B — Employee Review & Rewards System

Design a system that supports performance reviews and employee rewards with strong privacy and compliance.

Include:

Core features

Performance review cycles (self/manager/peer), calibration, and peer feedback
Reward points/grants, redemption, policies, and approval workflows
Privacy/visibility controls and audit trails

Architecture and integrations

Service boundaries and data models
Integrations with HRIS (org, titles, managers), SSO, and payroll/stock systems
Abuse/fraud prevention, rate-limiting, and anomaly detection

Operations

Observability, SLAs, and disaster recovery
Data retention, legal holds, and regional data residency

Provide data schemas, state machines, and key workflows. Call out edge cases, safeguards, and scale assumptions.

Design cron scheduler and reward/review system

Quick Overview

System Design: Company-Wide Scheduler Platform and Employee Review & Rewards System

Part A — Company-Wide Scheduled Job Platform (Cron-like)

Part B — Employee Review & Rewards System

Solution

Comments (0)

Design cron scheduler and reward/review system

Quick Overview

System Design: Company-Wide Scheduler Platform and Employee Review & Rewards System

Part A — Company-Wide Scheduled Job Platform (Cron-like)

Part B — Employee Review & Rewards System

Solution

Comments (0)