Building Marketcap.guide: Real-time Crypto Data Architecture
Technical breakdown of building a real-time cryptocurrency data platform - data ingestion, processing, caching, and serving millions of price updates.
Share the technical details of building your crypto data platform - from data sources to serving users.
Project Overview and Requirements
What to write about:
- What marketcap.guide provides to users
- Performance and reliability requirements
- Scale considerations (number of tokens, update frequency, users)
- Competitive landscape and differentiation
- Technical constraints and budget considerations
Explain what you built and why it required a sophisticated data architecture.
Data Source Strategy
What to write about:
- Which APIs and data providers you chose
- Evaluation criteria for data sources
- Handling multiple sources and data conflicts
- API rate limiting and cost management
- Backup strategies for data source failures
- Data quality and validation approaches
Discuss how you sourced and validated cryptocurrency market data.
Real-time Data Ingestion Pipeline
What to write about:
- Architecture for ingesting live price feeds
- Technologies used (WebSockets, message queues, etc.)
- Handling different update frequencies across tokens
- Batching vs real-time processing trade-offs
- Error handling and retry mechanisms
- Monitoring data ingestion health
Explain how you built the data ingestion system to handle continuous updates.
// Example of WebSocket data ingestion
const priceSocket = new WebSocket('wss://api.exchange.com/v1/stream');
priceSocket.on('message', (data) => {
const priceUpdate = JSON.parse(data);
// Validate and process price update
if (isValidPriceUpdate(priceUpdate)) {
updateQueue.push({
symbol: priceUpdate.symbol,
price: priceUpdate.price,
timestamp: Date.now(),
volume: priceUpdate.volume
});
}
});
Database Design and Storage Strategy
What to write about:
- Database technology choices (SQL vs NoSQL, time-series DBs)
- Schema design for price history and metadata
- Indexing strategies for fast queries
- Data retention and archival policies
- Backup and disaster recovery
- Scaling database reads and writes
Detail your database architecture and how you optimized for both writes and reads.
Caching and Performance Architecture
What to write about:
- Multi-layer caching strategy
- Cache invalidation and consistency challenges
- CDN usage for global performance
- In-memory vs distributed caching
- Cache warming strategies
- Performance monitoring and optimization
Explain how you achieved fast response times for users worldwide.
API Design and Rate Limiting
What to write about:
- REST API design principles you followed
- Rate limiting implementation and strategy
- Authentication and API key management
- Response format optimization
- Error handling and status codes
- API versioning strategy
Share how you designed the public API for developers and applications.
Frontend Performance and Real-time Updates
What to write about:
- Technology stack for the frontend
- Real-time price updates to users
- Optimizing for mobile performance
- State management for thousands of tokens
- Progressive loading and lazy loading
- SEO considerations for crypto data
Discuss the frontend challenges of displaying real-time financial data.
Monitoring, Alerting, and Observability
What to write about:
- Key metrics you track (latency, accuracy, uptime)
- Alerting for data quality issues
- Performance monitoring across the stack
- Log aggregation and analysis
- Error tracking and debugging
- Business metrics and user analytics
Explain how you monitored the health and performance of your data pipeline.
Scaling Challenges and Solutions
What to write about:
- Traffic spikes during market volatility
- Database scaling strategies
- Auto-scaling infrastructure decisions
- Cost optimization techniques
- Performance bottlenecks you discovered
- Architecture evolution as you grew
Share specific scaling challenges and how you solved them.
Data Quality and Accuracy
What to write about:
- Detecting and handling bad data
- Cross-validation between data sources
- Handling market manipulation and flash crashes
- Data audit trails and corrections
- User reporting of data issues
- Regulatory and compliance considerations
Discuss how you ensured data accuracy and reliability.
Lessons Learned and Architecture Evolution
What to write about:
- Major architectural decisions you'd change
- Technologies that worked well vs disappointments
- Unexpected challenges and solutions
- Cost vs performance trade-offs
- What you learned about crypto market data
- Future improvements and features
Reflect on the technical journey and what you'd do differently.
Include architecture diagrams, performance metrics, and code examples. Share specific numbers around throughput, latency, and scale to make this a practical reference for others building similar systems.