KKKrishna Kumar Mahtoinbackend.krishnakrmahto.com·Apr 15 · 4 min readIf AI Writes Code, Where Do Guardrails Live - a ConjectureGuardrails in software engineering are often misunderstood. Most engineers associate guardrails with: null checks validations defensive coding That is only a small part of the story. A more accur00
KKKrishna Kumar Mahtoinbackend.krishnakrmahto.com·Oct 14, 2025 · 7 min readUnderstanding Garbage Collection (GC) and Stop-The-World (STW) in the JVMThis guide explains — step by step — how the JVM’s garbage collector actually works.We’ll start from how memory is structured (Eden, Survivor, Old), move to what happens during a Minor GC, then see what Stop-The-World (STW) really means, and finally ...00
KKKrishna Kumar Mahtoinbackend.krishnakrmahto.com·Sep 18, 2025 · 5 min readWrite-Ahead Logging (WAL) in PostgreSQL: How It WorksPostgreSQL guarantees durability using Write-Ahead Logging (WAL). WAL ensures that once a transaction is committed, its changes survive crashes, even if the actual table or index pages were never written to disk at the time of failure. This article g...00
KKKrishna Kumar Mahtoinbackend.krishnakrmahto.com·Sep 16, 2025 · 5 min readHow PostgreSQL VACUUM Works: Dead Tuples, FSM/VM, and LockingPostgreSQL uses MVCC (Multi-Version Concurrency Control).Each UPDATE inserts a new row version (xmin = current XID) and marks the old one dead (xmax = current XID).Each DELETE marks the row dead by setting xmax. Dead tuples remain on disk, still refe...00
KKKrishna Kumar Mahtoinbackend.krishnakrmahto.com·Sep 13, 2025 · 4 min readHow PostgreSQL Decides Row Visibility with MVCCPostgreSQL implements MVCC (Multi-Version Concurrency Control) so that transactions see a consistent view of data while minimizing blocking.This design is central to PostgreSQL’s ability to balance consistency with concurrency. Tuple metadata: xmin ...00
