---
title: "Case Studies"
description: "In-depth engineering case studies: the problem, the constraints, the architecture decisions, how it was built, and the measurable results."
author: "Mohammad Abu Mattar"
canonical: https://mkabumattar.com/case-studies
---

# Case Studies

4 entries.

- [Zero-Downtime PostgreSQL Major-Version Upgrade at Scale](https://mkabumattar.com/case-studies/post/zero-downtime-postgres-upgrade) — How we moved a multi-terabyte PostgreSQL 12 database to 16 with no maintenance window, using logical replication, dual-read validation, and a rehearsed, timed cutover with a real rollback trigger.
- [Migrating a Monolith to Kubernetes Without a Big-Bang Cutover](https://mkabumattar.com/case-studies/post/monolith-to-kubernetes-strangler-migration) — Using the strangler-fig pattern to move a large monolith onto EKS service by service, with a routing facade, gradual traffic shifting, and a rollback at every step.
- [Cutting a SaaS AWS Bill 41% Without Slowing Delivery](https://mkabumattar.com/case-studies/post/aws-cost-optimization-saas-case-study) — A FinOps case study on a SaaS running on EKS with full GitOps and progressive delivery: how tagging, right-sizing node groups, and Savings Plans matched to the roadmap cut the AWS bill without freezing feature work.
- [QuenchWorks: Building a 0-CVE Container Image and Helm Chart Catalog](https://mkabumattar.com/case-studies/post/quenchworks-zero-cve-catalog) — How a from-scratch catalog replaced Bitnami with 150+ container images and 120+ Helm charts built from source on Wolfi, gated to zero fixable CVEs, signed, and pinned by digest.