https://hnnguyen.dev/en/ Practical engineering insights on backend systems, frontend architecture, DevOps, and real-world software development. en Mon, 31 Aug 2026 03:50:50 GMT https://hnnguyen.dev/en/blog/building-a-secure-and-scalable-asset-storage-architecture-with-aws-s3-and-cloudfront https://hnnguyen.dev/en/blog/building-a-secure-and-scalable-asset-storage-architecture-with-aws-s3-and-cloudfront Wed, 24 Jun 2026 14:18:14 GMT Learn how to build a secure and scalable AWS asset storage architecture using Amazon S3, CloudFront, Origin Access Control, IAM, versioning, and lifecycle policies. https://hnnguyen.dev/en/blog/how-to-change-your-google-account-email-on-mobile https://hnnguyen.dev/en/blog/how-to-change-your-google-account-email-on-mobile Tue, 23 Jun 2026 11:47:15 GMT Learn how to change your Google Account email on your mobile device with this step-by-step guide. Check whether your account supports email address changes. https://hnnguyen.dev/en/blog/how-to-troubleshoot-a-spring-boot-application-that-keeps-stopping-on-an-ubuntu-vps https://hnnguyen.dev/en/blog/how-to-troubleshoot-a-spring-boot-application-that-keeps-stopping-on-an-ubuntu-vps Wed, 10 Jun 2026 06:14:53 GMT Troubleshoot Spring Boot crashes on Ubuntu VPS by diagnosing Nginx 502 errors, Java OOM Killer events, memory issues, and swap configuration. https://hnnguyen.dev/en/blog/how-i-fixed-a-spring-boot-application-that-kept-getting-killed-by-the-linux-oom-killer https://hnnguyen.dev/en/blog/how-i-fixed-a-spring-boot-application-that-kept-getting-killed-by-the-linux-oom-killer Wed, 03 Jun 2026 04:29:27 GMT Learn how I fixed Spring Boot OOM crashes on a 2GB Ubuntu VPS by diagnosing Linux OOM Killer events, configuring swap space, and stabilizing Java. https://hnnguyen.dev/en/blog/bangkok-through-my-lens-april-2026 https://hnnguyen.dev/en/blog/bangkok-through-my-lens-april-2026 Sat, 16 May 2026 14:26:54 GMT Explore photos from my April 2026 trip to Bangkok, Thailand, captured on a Sony A6400 with a Sigma 18-50mm F2.8, featuring authentic moments in natural light. https://hnnguyen.dev/en/blog/memory-tuning-for-spring-boot-on-a-2gb-ubuntu-vps https://hnnguyen.dev/en/blog/memory-tuning-for-spring-boot-on-a-2gb-ubuntu-vps Mon, 06 Apr 2026 03:45:50 GMT Learn the Spring Boot memory settings I use on a 2GB Ubuntu VPS, including JVM options, systemd limits, swap space, and monitoring for stable performance. https://hnnguyen.dev/en/blog/why-a-2gb-vps-needs-swap-space-for-spring-boot-applications https://hnnguyen.dev/en/blog/why-a-2gb-vps-needs-swap-space-for-spring-boot-applications Tue, 10 Feb 2026 03:19:14 GMT Learn why a 2GB Ubuntu VPS needs swap space for Spring Boot, PostgreSQL, and Nginx to prevent Linux OOM Killer events and improve stability. https://hnnguyen.dev/en/blog/what-is-systemd-journald-and-should-you-limit-its-log-size https://hnnguyen.dev/en/blog/what-is-systemd-journald-and-should-you-limit-its-log-size Sat, 10 Jan 2026 03:03:14 GMT Discover how systemd-journald works, why it consumes RAM, and how to configure log retention on an Ubuntu VPS using journald.conf. https://hnnguyen.dev/en/blog/how-i-secured-my-ubuntu-vps-after-seeing-constant-ssh-attack-attempts https://hnnguyen.dev/en/blog/how-i-secured-my-ubuntu-vps-after-seeing-constant-ssh-attack-attempts Fri, 09 Jan 2026 04:00:17 GMT Secure your Ubuntu VPS with SSH keys, UFW, Fail2Ban, and automatic updates to reduce attack risks and protect against common SSH login attempts. https://hnnguyen.dev/en/blog/seoul-through-my-lens-november-2025 https://hnnguyen.dev/en/blog/seoul-through-my-lens-november-2025 Thu, 06 Nov 2025 07:18:27 GMT Explore Seoul through my November 2025 photo journal, featuring original iPhone photography that captures the city's autumn streets and everyday moments. https://hnnguyen.dev/en/blog/how-to-install-cursor-ide-on-ubuntu https://hnnguyen.dev/en/blog/how-to-install-cursor-ide-on-ubuntu Thu, 04 Sep 2025 10:49:36 GMT Install Cursor IDE on Ubuntu using the AppImage package. Follow this step-by-step guide to configure desktop integration, launcher scripts, and AppArmor. https://hnnguyen.dev/en/blog/login-to-github-on-macos-using-ssh-key https://hnnguyen.dev/en/blog/login-to-github-on-macos-using-ssh-key Fri, 29 Aug 2025 10:49:53 GMT Set up SSH keys for GitHub on macOS to securely clone, pull, and push repositories without entering your password for every Git operation. https://hnnguyen.dev/en/blog/sessions-vs-jwts-understanding-authentication-in-modern-web-applications https://hnnguyen.dev/en/blog/sessions-vs-jwts-understanding-authentication-in-modern-web-applications Fri, 01 Aug 2025 12:07:48 GMT Understand why HTTP is stateless and how Session-Cookie and JWT authentication solve user identity across requests, with their pros, cons, and use cases. https://hnnguyen.dev/en/blog/how-to-run-java-jar-application-with-systemd-on-linux-as-service https://hnnguyen.dev/en/blog/how-to-run-java-jar-application-with-systemd-on-linux-as-service Wed, 04 Jun 2025 07:59:58 GMT Run a Spring Boot JAR as a systemd service on Ubuntu. Configure startup, automatic restarts, resource limits, and service management commands. https://hnnguyen.dev/en/blog/installing-and-configuring-postgresql-with-open-port-access-on-ubuntu https://hnnguyen.dev/en/blog/installing-and-configuring-postgresql-with-open-port-access-on-ubuntu Tue, 03 Jun 2025 03:17:30 GMT Install and secure PostgreSQL on Ubuntu 22.04 with this step-by-step guide covering installation, authentication, remote access, firewall, and configuration. https://hnnguyen.dev/en/blog/setup-ssl-for-nginx https://hnnguyen.dev/en/blog/setup-ssl-for-nginx Mon, 02 Jun 2025 14:49:19 GMT Secure your Nginx server on Ubuntu with Let's Encrypt and Certbot. Configure HTTPS, obtain an SSL certificate, and enable automatic renewal. https://hnnguyen.dev/en/blog/how-to-install-nginx-on-ubuntu-22-04 https://hnnguyen.dev/en/blog/how-to-install-nginx-on-ubuntu-22-04 Sun, 01 Jun 2025 13:55:16 GMT Install and configure Nginx on Ubuntu 22.04 with this step-by-step guide covering firewall setup, server blocks, service management, and deployment. https://hnnguyen.dev/en/blog/initial-server-setup-with-ubuntu https://hnnguyen.dev/en/blog/initial-server-setup-with-ubuntu Sat, 31 May 2025 12:34:08 GMT Secure your new Ubuntu server from day one — create a sudo user, set up UFW firewall rules, and configure SSH access the right way. https://hnnguyen.dev/en/blog/the-fundamentals-of-photo-composition https://hnnguyen.dev/en/blog/the-fundamentals-of-photo-composition Fri, 30 May 2025 12:17:41 GMT Real-life examples through the lens of photographer Partho Protim Bhowmick. https://hnnguyen.dev/en/blog/how-to-quickly-identify-and-kill-applications-occupying-a-port-on-windows https://hnnguyen.dev/en/blog/how-to-quickly-identify-and-kill-applications-occupying-a-port-on-windows Fri, 30 May 2025 10:50:48 GMT Fix "port already in use" errors on Windows: find the process using netstat, get its PID, and kill it with taskkill — no third-party tools needed. https://hnnguyen.dev/en/blog/fixing-crlf-issues-in-git-enforcing-lf-for-your-project https://hnnguyen.dev/en/blog/fixing-crlf-issues-in-git-enforcing-lf-for-your-project Fri, 30 May 2025 10:50:21 GMT Fix "Expected linebreaks to be 'LF' but found 'CRLF'" on Windows by configuring Git's core.autocrlf and core.eol settings — global or per-project. https://hnnguyen.dev/en/blog/using-google-analytics-to-grow-your-business https://hnnguyen.dev/en/blog/using-google-analytics-to-grow-your-business Fri, 30 May 2025 09:47:08 GMT Learn how to use Google Analytics to grow your business — tips on Audience, Behavior, and Acquisition reports to find where to invest your marketing budget. https://hnnguyen.dev/en/blog/the-small-business-trifecta-google-visibility-web-accessibility-and-harnessing-ai https://hnnguyen.dev/en/blog/the-small-business-trifecta-google-visibility-web-accessibility-and-harnessing-ai Thu, 29 May 2025 12:27:30 GMT Learn how to get your business listed on Google, optimize your online presence, and use AI and accessibility tools to grow your digital footprint. https://hnnguyen.dev/en/blog/get-found-in-search-engines https://hnnguyen.dev/en/blog/get-found-in-search-engines Wed, 28 May 2025 07:04:44 GMT Learn how to get found in search engines with expert SEO tips on keyword research using SEMrush and Google, plus how to optimize titles, slugs, and meta descriptions. https://hnnguyen.dev/en/blog/no-code-low-code-tools-to-streamline-your-service-based-business https://hnnguyen.dev/en/blog/no-code-low-code-tools-to-streamline-your-service-based-business Wed, 28 May 2025 07:03:34 GMT Discover the best no-code/low-code tools to build your business tech stack — from client management and scheduling to social media and content creation. https://hnnguyen.dev/en/blog/graphic-design-best-practices-tools https://hnnguyen.dev/en/blog/graphic-design-best-practices-tools Wed, 28 May 2025 03:19:48 GMT Learn graphic design best practices and free tools like Canva, Snappa, and Google Fonts to create professional designs without technical skills. https://hnnguyen.dev/en/blog/establish-a-professional-domain-website-and-email-for-your-business https://hnnguyen.dev/en/blog/establish-a-professional-domain-website-and-email-for-your-business Mon, 26 May 2025 08:48:26 GMT Learn what a domain name is, how to choose and register one, build a free website with Google Sites, and set up professional business email. https://hnnguyen.dev/en/blog/ai-automation-in-small-businesses https://hnnguyen.dev/en/blog/ai-automation-in-small-businesses Mon, 26 May 2025 08:27:22 GMT Discover how Canva AI, ChatGPT, and Zapier can boost your small business - streamline design, content creation, and automation to save time and grow.