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Software EngineeringEngineeringPlatinum

Planning the architecture of a scalable online system.

System Design Interviewer

Distributed Systems, Scalability, CAP Theorem

expertv5.0

Best for

  • Design scalable chat systems with message ordering and presence guarantees
  • Architect URL shortener services with custom domain support and analytics
  • Build rate limiting systems with distributed token bucket implementation
  • Design news feed systems handling millions of users with personalization

What you'll get

  • Detailed system architecture diagram with numbered data flow, capacity calculations showing 50K QPS handling, and ADR explaining why Cassandra over PostgreSQL for time-series data
  • Load balancing strategy comparing round-robin vs consistent hashing with mathematical analysis of hotspot probability and failover scenarios
  • Database design with specific partitioning scheme, read replica topology, and cache invalidation strategy with concrete Redis TTL recommendations
Expects

Clear problem statement with scale requirements, performance constraints, and business context for architecture decisions.

Returns

Structured system design with component diagrams, capacity estimates, trade-off analysis, and architecture decision records with rationale.

What's inside

You are a Principal Systems Architect. You design complex distributed systems using rigorous engineering principles, not pattern matching. - **Clarify before designing.** You ask targeted questions about functional requirements, non-functional requirements (availability %, latency SLOs, throughput t...

Covers

What You Do DifferentlyMethodologyWatch ForOutput Format Format
Not designed for ↓
  • ×Writing actual implementation code for system components
  • ×Debugging existing production system performance issues
  • ×Providing specific vendor pricing or contract negotiations
  • ×Making final technology stack decisions without business context

SupaScore

89
Research Quality (15%)
9.25
Prompt Engineering (25%)
8.85
Practical Utility (15%)
8.5
Completeness (10%)
9.4
User Satisfaction (20%)
8.9
Decision Usefulness (15%)
8.7

Evidence Policy

Standard: no explicit evidence policy.

system-designarchitecturedistributed-systemsscalabilityload-balancingcachingdatabasescap-theoremtrade-offsinterview-prepmicroservices

Research Foundation: 6 sources (2 expert knowledge, 2 industry frameworks, 1 official docs, 1 community practice)

This skill was developed through independent research and synthesis. SupaSkills is not affiliated with or endorsed by any cited author or organisation.

Version History

v5.03/25/2026

v5.5 distilled from v2 via Claude Sonnet

v2.02/26/2026

Pipeline v4: rebuilt with 3 helper skills

v1.0.02/14/2026

Initial version

Works well with

Need more depth?

Specialist skills that go deeper in areas this skill touches.

Common Workflows

Complete System Design Interview

End-to-end system design from architecture through testing and monitoring implementation

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