Aqib Chattha — Engineering JournalWriting on Java, concurrency, caching, distributed batch processing, SQL at volume, payment systems and working effectively with AI coding agents.https://aqibchattha.comen-gb© 2026 Aqib ChatthaWhen Parallel Streams Become a Production Problemhttps://aqibchattha.com/journal/parallel-streams-in-productionhttps://aqibchattha.com/journal/parallel-streams-in-productionparallelStream() is one call away and looks like free concurrency. On I/O-bound work sharing a JVM-wide pool, it is a way to make unrelated code slow.Tue, 14 Jul 2026 00:00:00 GMTJavaConcurrencyPerformanceAqib ChatthaDesigning a Two-Level Cache with JCS and Redishttps://aqibchattha.com/journal/two-level-cache-designhttps://aqibchattha.com/journal/two-level-cache-designA local in-process cache in front of Redis buys latency and resilience. It bills you in invalidation. Here is the accounting.Sat, 02 May 2026 00:00:00 GMTCachingRedisArchitectureAqib ChatthaWhat AI Coding Agents Still Get Wrong About Distributed Systemshttps://aqibchattha.com/journal/what-ai-agents-misshttps://aqibchattha.com/journal/what-ai-agents-missAgents write correct-looking code very fast. The failures I keep seeing are not syntax or API misuse — they are assumptions about time, ordering and retries.Wed, 18 Mar 2026 00:00:00 GMTAIDistributed SystemsEngineering practiceAqib Chattha