Project & Reading Plan

Set up and connect to a Redis instance from a Node.js application.

Implement a cache-aside strategy using Redis to store and retrieve Reddit API responses.

Cache pre-computed text embeddings in Redis to avoid redundant generation on each request.

Configure Time-To-Live (TTL) expiration rules to balance data freshness and cache performance.

Measure the latency reduction of search requests served from cache versus live API calls.

Explain the role of message brokers and job queues in decoupling long-running tasks from synchronous requests, referencing DDIA concepts.

Refactor the search process to offload Reddit API fetching and embedding generation to a background worker using BullMQ.

Establish a persistent, real-time connection between an Express.js server and a client using WebSockets.

Implement a workflow to notify the client via WebSockets when a background search job is complete and results are ready.

Explain the concept of vector embeddings and their storage in a relational database using an extension like pgvector.

Modify the PostgreSQL schema to include a vector column for storing text embeddings.

Create a background process to periodically fetch data, generate embeddings, and persist them in PostgreSQL.

Rewrite the search functionality to perform hybrid search directly within PostgreSQL, combining vector similarity and full-text search.

Benchmark the performance of database-native hybrid search against the previous cached, in-memory implementation.

Compare the trade-offs of relational and document data models for different application use cases (DDIA Ch. 2).

Describe how B-tree storage engines power indexing and transactions in PostgreSQL (DDIA Ch. 3).

Explain the ACID properties and the concurrency challenges that necessitate different transaction isolation levels (DDIA Ch. 7).

Distinguish between single-leader, multi-leader, and leaderless replication architectures and their consistency guarantees (DDIA Ch. 5 & 6).

Analyze an existing PostgreSQL schema and apply normalization principles to improve data integrity and reduce redundancy.

Implement robust, ACID-compliant database transactions for critical business operations like concurrent stock updates.

Use `EXPLAIN ANALYZE` to identify slow queries and apply appropriate indexing strategies to optimize performance.

Implement role-based access control (RBAC) middleware in Express.js to secure sensitive API endpoints for inventory management.