Engineering

Horizontal vs vertical scaling, load balancing strategies, and when to introduce caching layers. CAP theorem in practice.

Topics, partitions, consumer groups, and offset management. Producer acknowledgment levels and delivery guarantees.

Token bucket vs sliding window algorithms. Distributed rate limiting with Redis. API gateway implementation patterns.

RESTful constraints, idempotency, versioning strategies, pagination patterns, and error response standardization.

Outbox pattern for transactional messaging. Saga orchestration vs choreography. Handling event ordering and idempotent consumers.

Cache-aside, write-through, write-behind patterns. Redis data structures for real-time use cases. Cache invalidation strategies.

Consensus algorithms, leader election, distributed locking. Two-phase commit vs eventual consistency tradeoffs.

High-dimensional vector embeddings, cosine similarity, HNSW index structure. pgvector vs dedicated vector databases.