Amazon·Software Engineer·Onsite - System Design / Architecture·Senior

Senior

Apr 2026

Summary

Amazon system design round for a software engineering role. The question was a beast, one of those multi-layered platform problems where you're not just designing a system but also arguing for organizational guardrails. Left feeling like I only scratched the surface.

Questions Asked (1)

Design a multi-tenant data ingestion and processing platform that serves thousands of internal teams, each with different schemas and SLA requirements. The design must address tenant isolation, noisy neighbor problems, control plane vs data plane separation, cost efficiency, and long-term maintainability.

System DesignTechnical Trade-offsData Modeling

Author's notes

This question has so many layers that I made the mistake of trying to address all of them upfront instead of picking a thread and pulling it.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and scale, then propose a layered architecture that separates the control plane (tenant management, schema registry, SLA policies) from the data plane (ingestion, processing, storage). Address tenant isolation and noisy neighbor mitigation through per-tenant resource quotas, partitioning, and possibly dedicated cells for high-tier tenants, while emphasizing cost efficiency via shared infrastructure and auto-scaling. Conclude with trade-offs around maintainability, such as schema evolution and operational tooling.

Pro tip: Tie every design decision back to Amazon's leadership principles, especially Customer Obsession and Frugality, and explicitly discuss how you'd measure success (e.g., SLA compliance, cost per tenant, onboarding time).

1. Clarify Requirements and Scale

Ask questions to understand tenant count, data volume, schema variability, SLA tiers, and budget constraints. Establish non-functional requirements like latency, throughput, and durability.

2. Design Control Plane vs Data Plane

Separate the control plane (tenant onboarding, schema registry, SLA policy management, monitoring) from the data plane (ingestion, processing, storage). Explain how this separation enables independent scaling and fault isolation.

3. Address Tenant Isolation and Noisy Neighbors

Propose isolation strategies: logical (shared infra with per-tenant quotas, rate limiting, and partitioning) and physical (dedicated cells for premium tenants). Discuss trade-offs between cost and isolation.

4. Ensure Cost Efficiency and Maintainability

Leverage shared, multi-tenant infrastructure with auto-scaling and tiered storage. Implement schema evolution, versioning, and self-service tools to reduce operational overhead and long-term maintenance.

5. Discuss Trade-offs and Evolution

Summarize key trade-offs (e.g., isolation vs cost, flexibility vs complexity) and outline a phased rollout plan. Mention how the design can evolve with changing requirements.

Key Points to Mention

Control plane and data plane separation for scalability and fault isolation
Tenant isolation mechanisms: logical (namespaces, quotas) and physical (dedicated cells)
Noisy neighbor mitigation: rate limiting, resource quotas, and priority queues
SLA management: tiered SLAs, monitoring, and alerting per tenant
Cost efficiency: shared infrastructure, auto-scaling, and storage tiering
Schema evolution and maintainability: schema registry, versioning, and self-service onboarding

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.