Search

DNS Lookup Tool

Check A, AAAA, MX, TXT and NS records live.

Mail Health Checker

Verify MX, SPF, DKIM and DMARC configuration.

SSL Checker

Inspect TLS certificate validity, expiry and chain of trust.

WHOIS Lookup

Check registrar, registration date and nameservers.

HTTP Header Checker

Inspect response headers and security headers.

Technology Detector

Identify the CMS, framework and hosting stack of any domain.

ATS Resume Checker

Score your resume against ATS parsing rules and keywords.

Resume Builder

Build an ATS-friendly resume from a template.

Cover Letter Generator

Generate a tailored cover letter.

Job Matcher

Match your resume against a job description.

Interview Prep

Practice likely interview questions for your target role.

Linux Administrator Roadmap

Filesystem to firewall — everything to run production Linux servers with confidence.

AWS Cloud Engineer Roadmap

From IAM to production architecture — build and secure real cloud infrastructure.

DevOps Engineer Roadmap

Version control, containers, CI/CD, and infrastructure as code, tied together.

Linux Fundamentals

Core concepts: the shell, commands, filesystem hierarchy, and how distributions differ.

Filesystem

The FHS layout, mount points, inodes, and navigating the filesystem like an administrator.

Permissions

Owners, groups, chmod/chown, and the sticky/SUID/SGID bits that trip up beginners.

Users & Groups

Creating and managing users, groups, sudoers, and password policies.

Process Management

ps, top, kill, signals, and understanding what's actually running on a server.

Package Management

yum/dnf, apt, and rpm — installing, updating, and removing software safely.

Networking

IP addressing, routing, DNS resolution, and diagnosing connectivity issues.

SSH

Key-based auth, hardening sshd_config, and tunneling.

Apache

Virtual hosts, modules, and troubleshooting the Apache web server.

Nginx

Reverse proxying, load balancing, and Nginx as a high-performance web server.

Systemd

Units, targets, journald, and managing services the modern way.

Cron

Scheduling recurring jobs and avoiding the classic cron pitfalls.

Shell Scripting

Bash scripting for real automation — loops, conditionals, and error handling.

Storage

Disks, partitions, filesystems, and mounting storage correctly.

LVM

Logical volumes, extending storage live, and snapshotting for safe rollbacks.

Firewalld

Zones, rich rules, and managing the firewall without downtime.

SELinux

Contexts, booleans, and troubleshooting SELinux denials instead of disabling it.

Monitoring

Watching CPU, memory, disk, and services proactively before they page you.

Backups

Backup strategies, rsync, and verifying restores actually work.

Security

Hardening a server: patching, auditing, and reducing the attack surface.

RHCSA Preparation

Exam objectives, practice tasks, and time-boxed drills for the RHCSA.

Production Linux Administration

Running Linux servers at scale — the habits that separate hobbyists from professionals.

AWS Basics

The AWS global infrastructure: regions, availability zones, and the console/CLI.

IAM

Users, roles, policies, and the principle of least privilege.

EC2

Launching, sizing, and connecting to virtual servers in the cloud.

EBS

Block storage volumes, snapshots, and choosing the right volume type.

VPC

Building your own isolated network inside AWS.

Subnet

Public vs private subnets and carving up your VPC's address space.

Internet Gateway

Giving a VPC internet access the right way.

Route Tables

Controlling traffic flow between subnets, gateways, and the internet.

Security Groups

Stateful instance-level firewalls and least-privilege network access.

NACL

Stateless subnet-level access control as a second line of defense.

Load Balancer

ALB/NLB routing, target groups, and health checks.

Auto Scaling

Scaling policies that grow and shrink capacity automatically.

S3

Object storage, bucket policies, versioning, and static website hosting.

CloudFront

CDN caching, origins, and distributing content globally.

Route53

DNS records, routing policies, and health-check-based failover.

Certificate Manager

Free, auto-renewing TLS certificates for your AWS resources.

RDS

Managed relational databases, backups, and Multi-AZ failover.

CloudWatch

Metrics, alarms, dashboards, and logs for real observability.

SNS

Pub/sub notifications for alerts and decoupled architectures.

SQS

Durable message queues for decoupling services.

Lambda

Running serverless functions without managing servers.

CloudFormation

Infrastructure as code — provisioning AWS resources from templates.

Cost Optimization

Right-sizing, reserved capacity, and catching wasted spend.

AWS Security Best Practices

Guardrails, encryption, and the Well-Architected security pillar.

Production Architecture

Wiring these services together into a real, resilient production system.

Linux

The Linux fundamentals every DevOps engineer needs before touching infrastructure.

Git

Version control fundamentals — commits, branches, and merges.

GitHub

Pull requests, Actions triggers, and collaborating on GitHub.

Bitbucket

Repositories, pipelines, and branch permissions in Bitbucket.

Docker

Containerizing applications with Dockerfiles and images.

Docker Compose

Defining and running multi-container applications.

Kubernetes

Orchestrating containers at scale — pods, deployments, and services.

Helm

Packaging and templating Kubernetes applications.

Jenkins

Building CI/CD pipelines that test and deploy automatically.

GitHub Actions

Workflow-as-code CI/CD directly inside GitHub.

Terraform

Provisioning cloud infrastructure as versioned, reviewable code.

Ansible

Agentless configuration management and idempotent playbooks.

Nexus

Hosting artifacts and container images in a private registry.

SonarQube

Enforcing code quality gates inside your pipeline.

Prometheus

Pull-based metrics collection and alerting rules.

Grafana

Visualizing metrics into dashboards that are actually useful.

Nagios

Classic host and service monitoring with alerting.

Wazuh

Security monitoring, detection rules, and SIEM fundamentals.

Cloudflare

DNS, CDN, and WAF in front of production traffic.

AWS

The core cloud platform most DevOps roles are built on.

Monitoring

Tying metrics and alerting together into real observability.

Logging

Centralizing and searching logs across a distributed system.

CI/CD

Designing pipelines that build, test, and ship safely on every commit.

Infrastructure as Code

Treating infrastructure like software — versioned, reviewed, reproducible.

Production Deployment

Blue-green, canary, and rollback strategies for shipping safely.

DevSecOps

Baking security into the pipeline instead of bolting it on after.

AWS Static Website Hosting

Production-grade static site delivery pipeline using S3 origin storage, CloudFront edge caching, ACM-issued TLS, Route53 DNS, and Cloudflare in front for extra security and performance.

AWS Dynamic Website Hosting

Full dynamic web application stack on EC2 with an RDS-backed database, CloudFront + S3 for static assets, ACM TLS, Route53 DNS, and Cloudflare protection in front of the origin.

Linux Administration: The Complete Field Guide

Filesystem hierarchy, permissions, users & groups, systemd, journald, cron, networking, SSH hardening, disk management, LVM, and RHCSA exam tips.

Docker in Production: Images, Volumes, Networks & Compose

Containers, images, volumes, networks, Dockerfiles, Compose stacks, private registries, and the troubleshooting playbook for production containers.

Git Mastery: Branching, Rebasing & GitHub Workflows

Git internals, branching, merging, rebasing, cherry-picking, stashing, resetting, reverting, tagging, Git Flow, and resolving merge conflicts for real.

AWS for DevOps: IAM, EC2, VPC, S3 & Deployment Patterns

IAM, EC2, S3, Route53, CloudFront, ACM, RDS, CloudWatch, VPC, ALB, and Security Groups — with real deployment architectures and interview questions.

Jenkins CI/CD: Pipelines, Agents & Deployments

Installation, declarative pipelines, agents, credentials, GitHub/Bitbucket webhooks, deployment stages, and pipeline troubleshooting.

Ansible Automation: Inventory, Playbooks & Roles

Inventory files, playbooks, variables, roles, handlers, Ansible Vault, and real-world playbooks for hardening and deploying servers at scale.

Cloudflare: DNS, SSL, Caching, WAF & Tunnels

DNS management, SSL/TLS modes, caching rules, firewall, WAF, rate limiting, page rules, origin certificates, and Cloudflare Tunnel.

Bitbucket: Repositories, Pipelines & Deployments

Repository setup, Bitbucket Pipelines YAML, branching permissions, pull requests, and deployment stages to servers and cloud targets.

SonarQube: Quality Gates & CI Integration

Installation, quality profiles, quality gates, scanner configuration for multiple languages, and wiring SonarQube into a CI/CD pipeline.

cPanel & WHM: Accounts, Email, DNS & Troubleshooting

Account management, email configuration, backups, SSL, DNS zones, PHP versions, and MySQL administration through cPanel/WHM.

Nagios Monitoring: NRPE, Checks & Alerting

Nagios Core installation, NRPE agent setup, host and service checks, notification/escalation rules, and the commands you'll run daily.

OWASP Top 10: Vulnerabilities, Exploits & Fixes

SQL injection, XSS, CSRF, RCE, and the rest of the OWASP Top 10 — with vulnerable/fixed code examples and the security headers that stop them.

Wazuh: SIEM Architecture, Agents & Detection Rules

Wazuh manager/indexer/dashboard architecture, agent deployment, custom detection rules, alert tuning, and the operational dashboard workflow.

Linux File Permissions, Ownership & umask Explained

The rwx permission model, chmod symbolic vs. octal notation, chown/chgrp, setuid/setgid/sticky bits, and how umask sets your defaults.

Cron & systemd Timers: Scheduling Jobs in Linux

Crontab syntax, special strings, run-parts directories, and modern systemd timer units — with a direct comparison of when to use each.

SSH Hardening: Key-Based Auth, Fail2ban & Bastion Hosts

Disabling password auth, key-based login, sshd_config hardening, fail2ban jails, and bastion-host architecture for production access.

LVM: Logical Volume Management from Scratch

Physical volumes, volume groups, and logical volumes — creating, extending, and shrinking storage without unmounting production filesystems.

AWS IAM Fundamentals: Users, Roles, Policies & Least Privilege

Users vs. roles vs. groups, identity-based vs. resource-based policies, policy evaluation logic, and applying least privilege in practice.

EC2 Instance Types & Purchasing Options

Instance family naming (m6i, c7g, r6g), On-Demand vs. Reserved vs. Spot vs. Savings Plans, and picking the right combination for a real workload.

S3 Storage Classes & Lifecycle Policies

Standard, Intelligent-Tiering, Glacier and Deep Archive compared on cost/retrieval time, plus lifecycle rules that move and expire objects automatically.

VPC Networking: Subnets, Route Tables & Security Groups

CIDR planning, public vs. private subnets, route tables, internet/NAT gateways, security groups vs. NACLs, and a reference 2-tier VPC design.

Git Branching Strategies: Git Flow vs. Trunk-Based Development

Git Flow's branch model compared against trunk-based development with short-lived feature branches and feature flags — with a decision framework.

Docker Compose for Multi-Container Applications

compose.yaml services, networks, volumes, environment files, healthchecks, and dependency ordering for a real app + database + cache stack.

Kubernetes Pods, Deployments & Services Explained

The Pod as the atomic unit, Deployments for replica management and rollouts, and Services (ClusterIP/NodePort/LoadBalancer) for stable networking.

Terraform State Management & Remote Backends

Why state exists, the danger of local state on a team, S3 + DynamoDB remote backends with state locking, and recovering from state drift.

How ATS Resume Screening Actually Works

What an Applicant Tracking System parses, why tables/columns/images break parsing, keyword matching mechanics, and how to format around it.

DevOps Resume: Structure, Keywords & Examples

Section order for a DevOps/SRE resume, which tools and metrics recruiters scan for first, and a before/after bullet-point rewrite.

Linux Commands Cheat Sheet

The commands used daily for filesystem navigation, permissions, processes, networking, storage, and service management on any Linux distribution.

Docker Commands Cheat Sheet

Images, containers, volumes, networks, Compose, and the cleanup/debug commands used to operate containers day to day.

Git Commands Cheat Sheet

Branching, merging, rebasing, stashing, and the recovery commands that get you out of a bad state without losing work.

Linux Interview Questions & Answers

Real questions asked in Linux SysAdmin, DevOps, and RHCSA-track interviews — filesystem, permissions, systemd, networking, storage, and troubleshooting.

AWS Interview Questions & Answers

Real questions asked in AWS Cloud, DevOps, and Solutions Architect interviews — IAM, EC2, S3, VPC, RDS, CloudFront, and cost/architecture tradeoffs.

Red Hat Certified System Administrator (RHCSA)

Issued by Red Hat

#AWS

6 articles tagged #AWS.

#DevOps

6 articles tagged #DevOps.

#Linux

5 articles tagged #Linux.

#Security

5 articles tagged #Security.

#CI/CD

4 articles tagged #CI/CD.

#Cloud

4 articles tagged #Cloud.

#Automation

3 articles tagged #Automation.

#Containers

3 articles tagged #Containers.

#Git

3 articles tagged #Git.

#RHCSA

3 articles tagged #RHCSA.

#Career

2 articles tagged #Career.

#Compose

2 articles tagged #Compose.

#Cost Optimization

2 articles tagged #Cost Optimization.

#Docker

2 articles tagged #Docker.

#EC2

2 articles tagged #EC2.

#IAM

2 articles tagged #IAM.

#IaC

2 articles tagged #IaC.

#Job Search

2 articles tagged #Job Search.

#Networking

2 articles tagged #Networking.

#Resume

2 articles tagged #Resume.

#Storage

2 articles tagged #Storage.

#Systemd

2 articles tagged #Systemd.

#Workflow

2 articles tagged #Workflow.

#systemd

2 articles tagged #systemd.

#ATS

1 article tagged #ATS.

#Alerting

1 article tagged #Alerting.

#Ansible

1 article tagged #Ansible.

#AppSec

1 article tagged #AppSec.

#Bitbucket

1 article tagged #Bitbucket.

#CDN

1 article tagged #CDN.

#Cloudflare

1 article tagged #Cloudflare.

#Code Quality

1 article tagged #Code Quality.

#Configuration Management

1 article tagged #Configuration Management.

#Cron

1 article tagged #Cron.

#DNS

1 article tagged #DNS.

#Detection

1 article tagged #Detection.

#DevSecOps

1 article tagged #DevSecOps.

#Email

1 article tagged #Email.

#Filesystem

1 article tagged #Filesystem.

#GitHub

1 article tagged #GitHub.

#Hardening

1 article tagged #Hardening.

#Hosting

1 article tagged #Hosting.

#Jenkins

1 article tagged #Jenkins.

#Kubernetes

1 article tagged #Kubernetes.

#LVM

1 article tagged #LVM.

#Monitoring

1 article tagged #Monitoring.

#NRPE

1 article tagged #NRPE.

#Nagios

1 article tagged #Nagios.

#OWASP

1 article tagged #OWASP.

#Orchestration

1 article tagged #Orchestration.

#Permissions

1 article tagged #Permissions.

#Pipeline

1 article tagged #Pipeline.

#Pipelines

1 article tagged #Pipelines.

#S3

1 article tagged #S3.

#SIEM

1 article tagged #SIEM.

#SSH

1 article tagged #SSH.

#Security Monitoring

1 article tagged #Security Monitoring.

#SonarQube

1 article tagged #SonarQube.

#SysAdmin

1 article tagged #SysAdmin.

#Terraform

1 article tagged #Terraform.

#VPC

1 article tagged #VPC.

#Version Control

1 article tagged #Version Control.

#WAF

1 article tagged #WAF.

#WHM

1 article tagged #WHM.

#Wazuh

1 article tagged #Wazuh.

#Web Security

1 article tagged #Web Security.

#cPanel

1 article tagged #cPanel.

Ranjith R

RHCSA-certified Linux administrator managing 400+ production domains, writing field-tested runbooks from real infrastructure work.