HomeRokibul Hasan Rokib is a full-stack software engineer in Dhaka, Bangladesh. Building web products at Programming Hero with Next.js, TypeScript, Express, MongoDB, and Redis.https://roqib.pro.bd/Focus Trackerhttps://roqib.pro.bd/projects/focus-tracker/https://roqib.pro.bd/projects/focus-tracker/A productivity app for focus sessions, streak tracking, gamification, and chart-based progress analytics.Sun, 08 Mar 2026 00:00:00 GMTQuickHirehttps://roqib.pro.bd/projects/quickhire/https://roqib.pro.bd/projects/quickhire/A job board with separate candidate and admin experiences, application tracking, and role-based access.Sun, 08 Mar 2026 00:00:00 GMTNetworking, SSH, SCP, curl, wget: Networking and Remote Access Fundamentalshttps://roqib.pro.bd/blog/15-networking-ssh-fundamentals/https://roqib.pro.bd/blog/15-networking-ssh-fundamentals/Learn essential networking concepts for DevOps, SSH key authentication, secure file transfers, and tools for HTTP requests and API testing.Mon, 05 Jan 2026 00:00:00 GMTLinux File System and Commands: A Hands-on Guidehttps://roqib.pro.bd/blog/14-linux-file-system-commands/https://roqib.pro.bd/blog/14-linux-file-system-commands/Learn Linux directory structure, navigation, permissions, user management, services, networking, and shell automation.Sun, 04 Jan 2026 00:00:00 GMTWhat Is DevOps? SDLC, CI/CD, and Shared Ownershiphttps://roqib.pro.bd/blog/13-what-is-devops/https://roqib.pro.bd/blog/13-what-is-devops/Learn the principles of DevOps, continuous delivery, infrastructure as code, and operational feedback.Sat, 03 Jan 2026 00:00:00 GMTSystem Design Fundamentals: A Practical Guidehttps://roqib.pro.bd/blog/10-system-design-fundamentals/https://roqib.pro.bd/blog/10-system-design-fundamentals/Explore architecture, reliability, networking, APIs, caching, load balancing, and database scaling.Thu, 20 Nov 2025 00:00:00 GMTBig-O Notation: Time and Space Complexityhttps://roqib.pro.bd/blog/09-time-complexity/https://roqib.pro.bd/blog/09-time-complexity/Compare constant, logarithmic, linear, quadratic, exponential, and factorial growth with practical code examples.Wed, 19 Nov 2025 00:00:00 GMTCloud Outages in 2025: Shared Dependencies and Failure Recoveryhttps://roqib.pro.bd/blog/07-cloud-architecture-reality/https://roqib.pro.bd/blog/07-cloud-architecture-reality/Explore DNS, control-plane, and configuration failures across cloud providers, and how to limit their blast radius.Tue, 18 Nov 2025 00:00:00 GMTInside the Operating System (Part 1)https://roqib.pro.bd/blog/05-operating-system/https://roqib.pro.bd/blog/05-operating-system/Understand OS history, bootloaders, kernels, memory protection, scheduling, and how programs run.Fri, 24 Oct 2025 00:00:00 GMTThe Evolution of Computer Architecture (Part 2)https://roqib.pro.bd/blog/04-computer-architecture-evolution/https://roqib.pro.bd/blog/04-computer-architecture-evolution/Follow computing from the abacus and mechanical engines to microprocessors, modern systems, and experimental architectures.Mon, 20 Oct 2025 00:00:00 GMTComputer Architecture: Inside the Machine (Part 1)https://roqib.pro.bd/blog/03-computer-architecture/https://roqib.pro.bd/blog/03-computer-architecture/Explore how the CPU, RAM, storage, and input/output devices work together to execute programs.Sun, 19 Oct 2025 00:00:00 GMTUnderstanding JSON Web Tokens (JWT)https://roqib.pro.bd/blog/02-json-web-token/https://roqib.pro.bd/blog/02-json-web-token/Learn JWT structure, Base64url encoding, HMAC signatures, authentication flows, and safe token validation.Fri, 17 Oct 2025 00:00:00 GMTDocker Deep Dive (Part 1): What Is Docker?https://roqib.pro.bd/blog/01-what-is-docker/https://roqib.pro.bd/blog/01-what-is-docker/Understand Docker images, containers, isolation, and why reproducible environments matter.Thu, 16 Oct 2025 00:00:00 GMT