Mohammad Abu Mattar
Hi, I’m Mohammad Abu Mattar
DevOps engineer, AWS-certified, working in the field since 2017. I run multi-account AWS platforms and production Kubernetes for fintech, where PCI-DSS sets the rules. On this site I write up what worked, what broke, and what I would do differently. Most of my tooling ends up open source.
Blog Posts
Bun vs. Node.js in Production: A Real-World Performance and Compatibility Breakdown
- Backend Development
- Software Engineering
- 26 Aug 2026
- 09 Mins read
The server-side JavaScript world in 2026 is comfortable with having more than one good option. Node.js has been the reliable workhorse for over a decade: stable, heavily tested, and predictable. Bun c
Introduction to Linux CLI
- Linux
- Command Line Interface
- 19 Oct 2022
- 51 Mins read
Introduction The Linux operating system family is a group of free and open-source Unix systems. They consist of Red Hat, Arch Linux, Ubuntu, Debian, openSUSE, and Fedora. You must use a shell when
Kubernetes Health Probes: Building Self-Healing Applications
- Kubernetes
- Site Reliability Engineering
- 15 Aug 2026
- 08 Mins read
Kubernetes has a reputation for keeping applications online, but it is not magic. Out of the box, the cluster is blind to what happens inside your container. If your application deadlocks or exhausts
Service Mesh Deep Dive: Istio vs. Linkerd
- Kubernetes
- Service Mesh
- 06 Apr 2026
- 19 Mins read
So, you're getting into cloud-native, huh? Managing all those microservices can get pretty tricky. As you break your apps into smaller, independent pieces, making sure they talk to each other reliably
AWS Lambda Observability: Monitoring with CloudWatch, X-Ray, and Datadog
- AWS Lambda
- Serverless
- 21 Mar 2026
- 26 Mins read
Why serverless observability is non-negotiable for AWS Lambda What is serverless computing and AWS Lambda? Serverless computing is a big change in how we build things in the cloud. It takes a
Designing SLOs and Error Budgets: Your Blueprint for Sustainable Reliability
Every business shipping software is trying to balance two big things: getting new features out fast and keeping their services super reliable. Every tech team deals with this, pushing for new ideas wh
Case Studies
Taming a 3am Pager: SLOs and Error Budgets That Stuck
- Reliability
- DevOps
- 29 Aug 2026
- 07 Mins read
A platform team was losing people to burnout, and the cause was the pager. On-call meant a phone that went off day and night with alerts about CPU, memory, and pod restarts, the overwhelming majority
Multi-Region Active-Active for a Payments API
- Architecture
- Cloud Computing
- 16 Aug 2026
- 06 Mins read
A payments API that moves real money had been running comfortably in a single AWS region for years. It was reliable until the day it was not: a regional control-plane incident took the whole service o
Building an Internal Developer Platform on Backstage and GitOps
- DevOps
- Platform Engineering
- 03 Aug 2026
- 09 Mins read
Product teams were spending more time waiting on the platform team than building features. Spinning up a new service meant opening a ticket and waiting for someone to provision a repo, wire up CI, wri
Zero-Downtime PostgreSQL Major-Version Upgrade at Scale
A multi-terabyte PostgreSQL 12 database was reaching end of life, and the business ran around the clock, so the usual answer of "schedule a maintenance window" was off the table. We upgraded it to Pos
Migrating a Monolith to Kubernetes Without a Big-Bang Cutover
- DevOps
- Cloud Native
- 20 Jul 2026
- 07 Mins read
Almost every failed "let's move off the monolith" project shares one detail: the plan was a big-bang cutover. Rewrite in parallel, pick a weekend, flip the switch, and pray. This is the opposite of th
Cutting a SaaS AWS Bill 41% Without Slowing Delivery
- Cloud Computing
- DevOps
- 19 Jul 2026
- 10 Mins read
A growing SaaS ran on EKS with a full GitOps pipeline, and it was over its AWS budget nearly every month. The reflex from leadership was the usual one: freeze features until the bill comes down. That
Cheatsheets
Code Snippets
Bash Script Locking: Prevent Concurrent Runs with a PID File
- Bash
- Automation
- 18 Aug 2026
- 04 Mins read
Quick Tip Wrap any script that must not run twice at once in a PID-file lock, and a second copy simply exits instead of corrupting your data. The Problem The Problem Cron does not c
AWS DynamoDB CRUD Operations in Node.js with the AWS SDK v3
Quick Tip Wrap the low-level DynamoDB client in a DynamoDBDocumentClient so you pass plain JavaScript objects in and get plain objects back, then guard your writes with ConditionExpression an
Python Async HTTP Requests with aiohttp: Fetch Multiple URLs Concurrently
Quick Tip Reuse one aiohttp session, fan your requests out with asyncio.gather, and cap them with a semaphore to fetch hundreds of URLs in the time one loop would take. The Problem **The
Bash Retry Function: Automatically Retry Failing Commands with Exponential Backoff
- Devops
- Shell scripting
- 20 Jul 2026
- 05 Mins read
Quick Tip Wrap any flaky command in one reusable retry function and stop re-running red pipelines by hand. The Problem The Problem Some commands fail for reasons that have nothing to
Node.js Environment Variable Validation with Zod at Startup
- Nodejs
- Typescript
- 27 May 2026
- 07 Mins read
Most Node.js apps treat process.env like a trusted friend. You reach into it whenever you need a value, assume the key is there, assume it's spelled right, and assume the string is actually the type
AWS EC2 Instance Management with Boto3: Start, Stop, and Query Instances
If you've ever spent 20 minutes clicking through the AWS Console just to stop a handful of dev instances, you already know the pain. It's tedious, it doesn't scale, and one wrong click can ruin your a
Dev Tips
Terraform Workspaces vs. Directory-Based Environments: What Actually Scales
- Cloud & Infrastructure Automation
- 19 Aug 2026
- 03 Mins read
Why this choice matters Hey, want to stop sweating every prod apply? The way you split dev, staging, and prod in Terraform decides how much damage a single mistake can do. Get it right and a
GitHub Actions Secrets and Environment Variables: Handle Config the Right Way
- DevOps & DevSecOps
- 08 Aug 2026
- 04 Mins read
Why secrets handling matters Most CI leaks are config mistakes, not attacks Hey, want to stop leaking credentials in your pipelines? Most secret leaks in CI are not the result of some cle
Docker Multi-Stage Builds: Smaller, Safer Images for Production
- Kubernetes & Containers
- 27 Jul 2026
- 04 Mins read
Why multi-stage builds matter Image size is really about what is inside Hey, want to stop shipping a toolshed to production? If your Dockerfile builds and runs the app in one stage, your
ArgoCD GitOps: Sync Kubernetes Deployments Automatically from Git
- Kubernetes & Containers
- 22 Jul 2026
- 04 Mins read
Why GitOps for Kubernetes? From kubectl apply to Git as the source of truth Hey, want to stop deploying to Kubernetes by hand? If your releases still come from someone running `kubectl ap
Kubernetes Namespaces: Organize, Isolate, and Secure Multi-Team Clusters
- Kubernetes & Cloud Native
- 28 May 2026
- 06 Mins read
Why cluster isolation matters The multi-tenant reality If you're running a separate cluster for every environment and every dev team, you have already seen the bill and the amount of upgrade
Helm Charts: Templating & Multi-Environment Kubernetes Deployments
- Kubernetes & DevOps
- 30 Mar 2026
- 04 Mins read
Why Helm matters The Kubernetes manifest problem Managing Kubernetes manifests at scale becomes a nightmare. You have a deployment for dev, staging and production. Each one is 90% identi
Flashcards
Docker and Container Fundamentals Flashcards
- Containers
- DevOps
- 41 Cards
- ~17 min
- 22 Aug 2026
A spaced-repetition deck covering images, containers, Dockerfiles, volumes, networking, Compose, and registries.
Terraform Associate Flashcards (TA-003)
- Terraform
- Certification
- Devops
- 61 Cards
- ~25 min
- 09 Aug 2026
Full exam coverage for the HashiCorp Certified Terraform Associate (TA-003) exam using spaced repetition. Covers IaC concepts, CLI, HCL, state, modules, backends, and Terraform Cloud.
Kubernetes Administrator Flashcards (CKA)
- Kubernetes
- Certification
- Devops
- 54 Cards
- ~23 min
- 28 Jul 2026
Full exam coverage for the Certified Kubernetes Administrator (CKA) exam using spaced repetition. Covers cluster architecture, workloads, scheduling, networking, storage, security, and troubleshooting.
AWS SysOps Administrator Associate Flashcards (SOA-C02)
- Aws
- Certification
- Devops
- 50 Cards
- ~21 min
- 28 May 2026
Full exam coverage for the AWS Certified SysOps Administrator Associate (SOA-C02) exam using spaced repetition. Covers monitoring, reliability, deployment, security, networking, and cost optimization.
LPIC-2 Linux Engineer Flashcards
- Linux
- Certification
- Sysadmin
- 77 Cards
- ~32 min
- 27 Apr 2026
Full exam coverage for the LPIC-2 Linux Engineer certification (Exam 201 & 202) using spaced repetition. Covers kernel, boot, storage, networking, security, DNS, web, email, and more.
AWS Certified Developer - Associate Flashcards (DVA-C02)
- Aws
- Cloud
- Certification
- 90 Cards
- ~38 min
- 26 Apr 2026
Full exam coverage for the AWS Certified Developer - Associate (DVA-C02) exam using spaced repetition. Covers Development, Security, Deployment, Troubleshooting, and AWS SDK/CLI/APIs.
Glossary
CI/CD & Automation
- Devops
- 35 Terms
- 23 Aug 2026
A quick-reference glossary of the terms you meet when automating builds, tests, and deployments: pipeline anatomy, test gates, and release strategies like canary and blue-green.
Kubernetes Advanced
- Kubernetes
- Platform
- 39 Terms
- 10 Aug 2026
This glossary covers the advanced Kubernetes terminology platform engineers rely on: scheduling, networking, storage, security, extensibility, and the workload controllers that keep applications runni
Cloud Computing on AWS
This glossary covers the essential Amazon Web Services terms every cloud engineer and architect should know: compute, storage, networking, databases, and the identity controls that keep it all secure.
Networking Fundamentals
- Networking
- Fundamentals
- 47 Terms
- 28 May 2026
This glossary covers the core networking concepts every developer, DevOps engineer, and system administrator should know: how data is layered and addressed, and how it gets routed across the internet.
Linux Server Administration
- Linux
- 60 Terms
- 18 Apr 2026
This glossary covers essential Linux server administration concepts: system architecture, user management, networking, storage, process management, performance tuning, and security hardening.
Containers & Kubernetes
- Devops
- 63 Terms
- 11 Apr 2026
This glossary covers essential terms for working with containers and Kubernetes: building Docker images, and managing workloads, networking, storage, scaling, and security in a Kubernetes cluster.
Quizzes
C# & .NET: Language and Runtime Fundamentals
Ready to test how well you know C# and the .NET runtime? This quiz walks through the type system, LINQ, async/await, the CLR and garbage collection, and modern features like records and pattern matchi
Spring Boot: Java Application Framework Essentials
- Spring Boot
- Java
- 20 Questions
- ~5 min
- 11 Aug 2026
- Level: Intermediate
Spring Boot removed most of the ceremony from Java backend development, but the framework still does a lot of work you cannot see. This quiz walks through dependency injection, auto-configuration, RES
Java: Core Language & JVM Fundamentals
Java has quietly powered banks, Android, and countless backend systems for decades, and the language keeps evolving with records, sealed classes, and virtual threads. This quiz walks through the core
Rust: Ownership, Borrowing & Memory Safety
- Rust
- Systems Programming
- 20 Questions
- ~5 min
- 28 May 2026
- Level: Intermediate
This quiz tests your grip on the parts of Rust that trip up newcomers and pay off later: ownership and moves, borrowing and lifetimes, traits and generics, pattern matching, error handling with `Resul
System Design & Architecture: Scalability & Resilience
- Architecture
- Software Engineering
- 20 Questions
- ~5 min
- 24 Mar 2026
- Level: Advanced
Welcome to the System Design & Architecture quiz! Test your knowledge on scalability, reliability, performance, trade-offs, distributed systems patterns, and architectural decisions for production sys
Testing Strategies: Unit, Integration, E2E
- Quality Assurance
- Testing
- 20 Questions
- ~5 min
- 23 Mar 2026
- Level: Intermediate
Welcome to the Testing Strategies Quiz! This quiz covers unit testing, integration testing, end-to-end testing, mocking, fixtures, code coverage, and more. Test your knowledge and understanding of the
Roadmaps
React Developer Beginner to Expert
- Web development
- All Levels
- 13 Stages
- 31 Topics
- 25 Aug 2026
React Developer Beginner to Expert This roadmap takes you from JavaScript prerequisites through JSX, hooks, and state management, and on to data fetching, meta-frameworks, performance, and testing.
Full-Stack Developer Beginner to Expert
- Web development
- All Levels
- 18 Stages
- 50 Topics
- 12 Aug 2026
Full-Stack Developer Beginner to Expert This roadmap walks you from your first web page to shipping and operating a complete production application. Work the stages in order. Build the frontend fun
Backend Developer Beginner to Expert
- Web development
- All Levels
- 17 Stages
- 57 Topics
- 02 Aug 2026
Backend Developer Beginner to Expert This roadmap walks you from your first server-side program to designing scalable, secure systems. Work through the stages in order. Nail a language, the command
Frontend Developer Beginner to Expert
- Web development
- All Levels
- 18 Stages
- 81 Topics
- 28 May 2026
Frontend Developer Beginner to Expert This roadmap walks you from absolute beginner to a strong, hireable frontend engineer. Work through the stages in order. The early ones build the mental model
Release Engineer Beginner to Expert
- Devops
- Cloud
- Release engineering
- All Levels
- 26 Stages
- 112 Topics
- 25 Apr 2026
This roadmap takes you from release engineering principles and version control mastery through to advanced GitOps patterns and multi-account AWS delivery at scale. Each stage builds on the last. Treat
Site Reliability Engineer Beginner to Expert
This roadmap takes you from the fundamentals of Linux and systems thinking through to advanced observability, chaos engineering, and SRE organisational culture. Each stage builds on the last and ties