Bloom filters shave 90% of negative lookups; HyperLogLog estimates cardinality without storing every user ID. Redis modules on ElastiCache for abuse detection and feed deduplication.
Cache-aside without an invalidation story ships stale pricing to 2% of users—the hardest 2% to debug. This guide layers CloudFront, ElastiCache, and DAX with TTL, event-driven purge, and when write-through beats cache-aside.
Redlock debates matter because ElastiCache is not a consensus system. Consistent hashing for sharding workers and ALB target stickiness—with DynamoDB conditional writes as the boring alternative.
A production-focused guide to Amazon RDS performance: EBS gp3 IOPS and throughput, Performance Insights, read replicas, RDS Proxy, and aggressive application caching with ElastiCache—without outdated patterns like MySQL query cache.
Savings Plans and Reserved Instances reduce the rate you pay. Architecture determines the volume you pay at. The most durable cost reductions in AWS come from designing systems that structurally generate less spend — not from negotiating a lower price for the same behavior.
A B2B SaaS stack that costs $500/month at launch does not need to cost $50,000/month at 100,000 users if the architecture decisions at each stage are deliberate. This is the end-to-end reference architecture with real cost numbers.
Redis and its fork Valkey reduce AWS costs beyond caching: rate limiting, session storage, and distributed coordination all have cheaper implementations via in-memory data structures than the AWS-managed alternatives. Here is how to use them.
Redis is fast — until your application retries on every cache miss and the Redis bill starts looking like the database bill. ElastiCache patterns, data structures, cluster modes, eviction policies, and the production patterns that actually reduce database load.
