System Design - databases
#01 Databases

Build a Change Data Capture Pipeline Premium

Design a CDC pipeline that streams every database write to downstream consumers in the order they occurred, preserves transactional boundaries, and guarantees no event is dropped even if a consumer is temporarily offline.

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#02 Databases

Build a Columnar Storage Engine with SSTable and Compaction Premium

Design a write-optimized storage engine that buffers writes in memory, flushes them to immutable SSTables on disk, and runs background compaction to merge files while keeping read amplification low.

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#03 Distributed Systems

Build a Distributed Key-Value Store Premium

Design a distributed KV store that partitions data using consistent hashing, replicates each key across N nodes for durability, and handles node failures with tunable consistency guarantees.

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#04 Distributed Systems

Build a Distributed Shopping Cart with Guest Session Merge Premium

Design a shopping cart system that persists items for guest users, merges the guest cart into the authenticated cart on sign-in, handles concurrent modifications, and survives server restarts.

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#05 Databases

Build a Distributed Write-Ahead Log Premium

Design a durable WAL that survives single-node crashes, replicates log entries across nodes before acknowledging writes, and supports point-in-time recovery by replaying from any checkpoint.

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#06 Databases

Build an Event Sourcing and CQRS Audit Trail Premium

Design an event-sourced system where every state change is stored as an immutable event, supports replaying 3 years of history to reconstruct any past state, and separates read and write models for query performance.

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#07 Performance

Build Faceted Search with Live Inventory Filters Premium

Design a search system that supports multi-dimensional filter combinations (brand, price, rating, availability) and reflects live inventory changes in filter counts within seconds of a product going out of stock.

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#08 Databases

Build a Geospatial Proximity Service Premium

Design a service that answers 'find all X within Y km of this location' in under 10ms at 500 million active entities, supports moving entities that update their location every few seconds.

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#09 Scalability

Build Google Search Autocomplete Premium

Design a typeahead suggestion engine that returns the top 10 relevant completions for any search prefix in under 50ms, personalizes results per user, and updates suggestions based on trending queries in near real-time.

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#10 Databases

Build a Hot-Cold Tiered Storage System Premium

Design an automated data tiering system that keeps frequently accessed data on fast NVMe SSDs, migrates aging data to object storage, and retrieves cold data transparently on access without application changes.

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