Distributed Rate Limiter & Token Bucket
Multi-region sliding window counters with local Envoy token buckets, async Redis sync, and fail-open circuit breaker policies.
System Design Interview Coach
From fuzzy problem prompt to principal-level architecture talk track.
Master distributed systems interviews with real-time architecture diagrams, 15-stage senior blueprints, capacity calculations, and battle-tested failure mode defense.
The Blueprint
How top-tier system design interviews are won.
ClawPad organizes answers into the structured sequence senior FAANG interviewers score against.
- 01
Requirements & Scope Framing
Clarify functional vs non-functional constraints, throughput targets (QPS, DAU), latency SLAs (p99 < 50ms), and storage retention bounds before touching architecture.
- 02
Capacity Planning & Math Estimation
Derive read/write QPS, memory caching requirements, bandwidth ingress/egress, and disk IOPS step by step; the desktop re-checks the capacity model's throughput and bandwidth arithmetic for consistency before rendering it.
- 03
Core API & Data Contracts
Draft REST/gRPC endpoint signatures, payload envelopes, idempotency keys, and error semantics that match production standards.
- 04
High-Level Architecture Diagrams
Render clear component topologies from edge API gateways down to service meshes, load balancers, caching layers, and asynchronous event streams.
- 05
Database Selection & Schema Design
Choose the right persistence engine (Postgres, ScyllaDB, Redis, DynamoDB) with indexing strategies, primary/foreign key relationships, and partition keys.
- 06
Deep Dives, Bottlenecks & Tradeoffs
Defend your design choices: Cache-aside vs write-through, single-leader vs multi-region Raft consensus, consistent hashing virtual nodes, and backpressure handling.
Core Architectures
Sample high-scale distributed systems covered.
Practice end-to-end designs across high-concurrency real-world patterns.
URL Shortener & Key Generation Service
Base62 key generation clusters, consistent hashing with 256 virtual nodes per shard, and Redis LRU caching for hot keys.
WhatsApp / Slack Chat Architecture
Long-lived WebSocket gateways, connection state stores, Kafka pub/sub messaging channels, and Cassandra/ScyllaDB message history partitions.
Twitter / X Timeline Feed System
Hybrid fanout-on-write vs fanout-on-read for celebrity accounts, Redis timeline caching, and asynchronous background worker pipelines.
System Design FAQ
Common questions on AI system design practice.
Understand the interview coaching flow before your next mock session.
How does ClawPad structure system design answers?
ClawPad breaks questions down into the exact sequence top tech hiring managers expect: Clarification, Capacity Estimation, API Contracts, High-Level Architecture, Deep Dives, and Failure-Mode Analysis, generating interactive diagrams side-by-side.
What level of seniority does ClawPad target?
ClawPad supports Junior, Mid-level, Senior, Staff, and Principal blueprints. Senior and Principal tracks emphasize failure modes, trade-offs, evolution under 100x load, and organizational SLAs.
How do the real-time architecture diagrams work?
ClawPad's native engine renders interactive SVG architecture topologies showing clients, gateways, microservices, caches, and database clusters as the answer streams in.
Are capacity estimation calculations verified?
Partly. System-design answers carry a capacity model, and the desktop checks that its peak requests per second and bytes per second follow from the stated daily requests, peak multiplier, and payload size before rendering. Storage totals and other figures are yours to re-derive.
Elevate your system design
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