Designing a Distributed Cache Inspired by The Lord of the Rings: One Insight to Rule Them All
The Quest Begins (The "Why") Ever felt like your application is constantly begging the database for the same piece of data over and over? I remember…
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Building Inventory Applications That Don’t Lose Track Of Their Inventory
Let’s imagine we have an inventory system. Two of its customers decide to order the last remaining unit of a given product at roughly the same time.…
Treat Sales Handoffs as Explicit Workflow States
Treat Sales Handoffs as Explicit Workflow States A sales workflow should not treat “notification sent” as equivalent to “owner accepted.” Those are…
I built a system design app that teaches why and helps you in interviews
SysDesign Studio is an open-source, interactive way to practice system design interviews. Evolve architectures step by step, trace failure paths, an…
ForgeZero and Gloria: Build Tooling for People Who Still Want to Know What Their CPU Is Doing
I'm Alex Voste, the person behind ForgeZero and its resident experimental language, Gloria. I'm not going to open with a mission statement. I'm goin…
How HuskHoard Talks to the Cloud (and Why It Beats Managing Buckets by Hand)
A question we keep getting from people trying HuskHoard for the first time is some version of: "So it archives to S3... but how is that different fr…
What Happens When Two Databases Both Say Yes
Hello, I'm Maneshwar, and I'm building LiveReview — a blast-radius aware AI code review built for your business-critical systems. Star us to help de…
System Design: How to Build a Networking Library Like Retrofit or OkHttp
System Design: How to Build a Networking Library Like Retrofit or OkHttp Networking is one of the most important infrastructure layers in a modern A…
Android System Design: A Complete Guide for Android Developers
Android System Design: A Complete Guide for Android Developers Modern Android development is no longer only about creating screens and connecting AP…
Split-Brain Needs a Cluster. Mine Happened on One Server.
Today I want to talk about split-brain. The name sounds dramatic, and the problem is dramatic too. One system splits into two halves, and each half…
Sentinel: The Watchdog and Derived Points
A door sensor that only reports when the door opens or closes can go months without sending anything. If nothing has happened, that silence is corre…
Caching from Zero to Production
Every backend eventually hits the same wall: the database cannot keep up, but the data barely changes. That is the moment caching stops being an opt…
Durable Actor Session Protocol: How DASP Solves State Persistence for Long-Running Agent Conversations
Most agent frameworks treat sessions as ephemeral. You refresh the page, the conversation dies. You restart the process, the context vanishes. DASP…
Building a Plugin (Microkernel) Architecture in Java
Ever been asked to add "just one more custom rule" to your application, only to watch your elegant logic turn into a massive, fragile switch stateme…
5 EDI Lessons Every API Developer Learns the Hard Way
5 EDI Lessons Every API Developer Learns the Hard Way You have probably never thought about EDI. It's the ancient technology your retail trading par…
Moving Carefully and Proving It: The Reality of Scaling Fintech Infrastructure
Building backend systems for fintech is fundamentally different from almost any other domain. The stakes are absolute, the edge cases are catastroph…
How Uber Computes Estimated Time of Arrival (ETA)
Short answer: how does Uber compute ETA? Uber snaps noisy GPS pings to the road network (map matching), finds candidate routes on a road graph, and…
trelix v3.2.2 to v3.3.8: A GitHub App Already Hardened and Running in Production, and a Connector That Never Touches a Pixel
docker run --entrypoint trelix-mcp ghcr.io/sairam0424/trelix:3.2.1 --help returns exit code 127: command not found. Not a typo, not a stale tag — th…
Designing a Flash-Sale Seat Reservation System in AWS (Part 2): Never Sell a Seat Twice
TL;DR: Every booking goes through one Redis Lua script. The script checks, in order, whether the candidate is already admitted, whether their level…
Your Agent's Retry Logic Is an Event-Driven Systems Problem
Most of the event-driven architecture I've built started the same way: a synchronous call chain that worked fine in a demo and fell over under real…
Transactional Outbox Pattern: Memory Queue for Speed, PostgreSQL for Recovery
In distributed systems, the Transactional Outbox Pattern is a common way to reliably publish events after a database transaction. The idea is simple…
Designing Deterministic AI Agent Loops: Architecture, Verification, and Replay State Machines
Designing Deterministic AI Agent Loops: Architecture, Verification, and Replay State Machines Most software engineers building with Large Language M…
Deterministic Software + Probabilistic Intelligence
What I learned after trying to make the combination scale. I thought I had found a simple formula. Deterministic software handles what we know how t…
Design YouTube — Video Upload, Transcoding & CDN Delivery at Scale (with Production .NET Code)
"Design YouTube" is where two systems live in one product, pulling in opposite directions. The write side is a brutal batch-processing problem: some…
From Physical Racks to Intelligent Modules: How the Meaning of Infrastructure Has Fundamentally Shifted
Infrastructure used to be something you could walk up to, touch, and hear humming in a raised-floor room. Capacity planning dominated the conversati…
The Software Engineer Interview Roadmap 2026 (with Resources)
Disclosure: This post includes affiliate links; I may receive compensation if you purchase products or services from the different links provided in…
Circuit Breaker Pattern
One-liner: A circuit breaker stops calling a failing service to give it time to recover — instead of hammering it with requests that are guaranteed…
How Uber Knows Your Driver Is 7 Minutes Away
Hello, I'm Maneshwar, and I'm building LiveReview — a blast-radius aware AI code review built for your business-critical systems. Star us to help de…
When Abstraction Becomes a Bottleneck: The Real Cost of Overengineering
Abstraction is one of the most powerful tools in software engineering. It hides complexity. It reveals intent. It reduces duplication. It makes syst…
Audit Log with Short-Lived Online Data
When a setting changes unexpectedly, engineers need three answers: what changed, who changed it, and what was there before? Recent investigations an…