RJRandhir Jassalinprepstack.hashnode.dev·Jun 14 · 4 min readWe Replaced REST with Kafka and Cut API Failures by 90% — A Production Cutover (.NET 9)TL;DR — We swapped Mattrx's inter-service REST calls for Kafka topics (multi-tenant marketing analytics SaaS, .NET 9 / ASP.NET Core, Azure SQL, ~3,200 req/sec peak). Over 8 weeks: end-to-end ingestion00
RJRandhir Jassalinprepstack.hashnode.dev·Jun 13 · 2 min readOur Azure Bill Spiked Overnight — Here's Exactly How We Cut It 60% (7 Real Fixes)We run a multi-tenant analytics SaaS on Azure (.NET 9 / ASP.NET Core, Angular 19, ~110k MAU, ~3,200 req/sec). The bill was a boring ~\(4,800/mo for a year, then it climbed to ~\)12,100/mo in three wee00
RJRandhir Jassalinprepstack.hashnode.dev·Jun 12 · 2 min read.NET 11 vs .NET 10: We Benchmarked Both on a Real Production App (Should You Upgrade?)We run a multi-tenant analytics SaaS on ASP.NET Core (~110k MAU, ~3,200 req/sec peak, ~95k LOC) and benchmarked .NET 9, .NET 10 (current LTS), and .NET 11 previews on the same harness and the same pro00
RJRandhir Jassalinprepstack.hashnode.dev·Jun 11 · 3 min readAngular State Management in 2026 — NgRx, Signals, NGXS, Akita Compared (with Real Numbers)TL;DR — We rebuilt Mattrx's Angular state layer over 8 months (Angular 16 → 19, ~22k LOC TS). State LOC 8,400 → 3,100 (-63%), state-related bundle 38 KB → 18 KB, /campaigns re-renders per filter keyst00
