A self-paced architecture course on building analytics systems that answer questions about data seconds old rather than hours old. It covers six stages: when real-time is genuinely warranted, the log and streaming layer, the real-time analytical database, stream processing and correctness, serving queries at low latency, and operating the system in production.

The recurring theme is that real-time costs substantially more than batch in money, complexity and on-call load, so the first job is deciding honestly whether the business need justifies it. Tech Skills Library is independent and issues no certification or credential.

Modules

Stage One — When Real-Time Is Warranted

Lessons

• The Honest Case for Real-Time Preview
• Where Batch Is Still the Right Answer
• Reference Architecture

Stage Two — The Log and Streaming Layer

Lessons

• How the Distributed Log Works
• Partitioning and Keys
• Schemas and Compatibility

Stage Three — The Real-Time Analytical Database

Lessons

• Why Columnar Databases Are Fast
• Table Design and Sort Keys
• Ingestion Patterns

Stage Four — Stream Processing and Correctness

Lessons

• Windowing and Time
• Delivery Guarantees and Idempotence
• Joins Enrichment and State

Stage Five — Serving Queries at Low Latency

Lessons

• Query Patterns That Stay Fast
• Concurrency and Resource Isolation
• APIs and What Users Actually See

Stage Six — Operating in Production

Lessons

• Monitoring the Pipeline
• Scaling and Failure Handling
• Cost Control and the Career Path