Notes on full-stack engineering, problem solving, and the occasional puzzle.https://myblog.jszsoft.com/https://myblog.jszsoft.com/posts/2026-04-25-pi-5-network-monitor-one-month-in/https://myblog.jszsoft.com/posts/2026-04-25-pi-5-network-monitor-one-month-in/A retrospective on the Pi 5 transparent network monitor — the bugs that bit, the dashboard rewrite, an AI-friendly export format, and the surprising things home devices do when no one is watching.Sat, 25 Apr 2026 12:00:00 GMThttps://myblog.jszsoft.com/posts/2026-04-19-raspberry-pi-5-network-monitor/https://myblog.jszsoft.com/posts/2026-04-19-raspberry-pi-5-network-monitor/Step-by-step guide to building a WiFi access point on a Pi 5 that logs every device's traffic — destination IPs, ports, and DNS queries — with a live web dashboard.Sun, 19 Apr 2026 12:00:00 GMThttps://myblog.jszsoft.com/posts/2022-03-28-find-maximum-sub-array/https://myblog.jszsoft.com/posts/2022-03-28-find-maximum-sub-array/A single-pass Kadane-style solution to the classic maximum sub array interview problem, with worked-through Java and Python implementations.Mon, 28 Mar 2022 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-09-11-another-one-to-calculate-area-of-the-shadow/https://myblog.jszsoft.com/posts/2021-09-11-another-one-to-calculate-area-of-the-shadow/Working out the shaded area inside a semicircle using elementary trigonometry — a New Zealand high-school puzzle I saw on TikTok.Sat, 11 Sep 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-09-10-simple-chatroom-application-using-stomp-and-sockjsclient/https://myblog.jszsoft.com/posts/2021-09-10-simple-chatroom-application-using-stomp-and-sockjsclient/Building a small React + Spring Boot chatroom that uses STOMP over SockJS with a RabbitMQ relay, including login/logout event broadcasting.Fri, 10 Sep 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-05-13-react-unit-testing-use-jest-and-testing-library/https://myblog.jszsoft.com/posts/2021-05-13-react-unit-testing-use-jest-and-testing-library/A practical guide to setting up Jest configuration and writing React unit tests with Testing Library and jest-when, including mocking i18n and API calls.Thu, 13 May 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-02-13-vba-output-utf-8-text-file/https://myblog.jszsoft.com/posts/2021-02-13-vba-output-utf-8-text-file/Fixing a VBA automation script so it writes UTF-8 text files that correctly preserve accented characters on both MacOS and Windows.Sat, 13 Feb 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-02-08-calculate-area-of-the-shadow/https://myblog.jszsoft.com/posts/2021-02-08-calculate-area-of-the-shadow/Solving a high school geometry puzzle by decomposing overlapping circle sectors into triangles and using the law of cosines to find the shadow area.Mon, 08 Feb 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-02-05-create-custom-windows-10-recovery-option/https://myblog.jszsoft.com/posts/2021-02-05-create-custom-windows-10-recovery-option/Step-by-step guide to replacing a factory recovery partition with a custom Windows 10 image using ADK, DISM, diskpart and a bootable Windows PE USB.Fri, 05 Feb 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2021-01-06-access-unsecured-site-in-chrome/https://myblog.jszsoft.com/posts/2021-01-06-access-unsecured-site-in-chrome/A quick tip: type thisisunsafe on the Chrome certificate warning screen to bypass the block and access sites with invalid certificates.Wed, 06 Jan 2021 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-12-23-use-vscode-for-java-development/https://myblog.jszsoft.com/posts/2020-12-23-use-vscode-for-java-development/Setting up VS Code as a Java IDE with the Java, Spring Boot and Gradle extension packs, plus configuring launch settings and debugging.Wed, 23 Dec 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-12-07-encryption-and-signing-using-asymmetric-key/https://myblog.jszsoft.com/posts/2020-12-07-encryption-and-signing-using-asymmetric-key/A walkthrough of using asymmetric keys with openssl to encrypt messages and sign data, showing the difference between encryption and signing workflows.Mon, 07 Dec 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-12-04-session-filter-check-user-session/https://myblog.jszsoft.com/posts/2020-12-04-session-filter-check-user-session/Implement a Spring Boot servlet filter backed by Redis session storage that redirects unauthenticated users to the login page.Fri, 04 Dec 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-18-install-and-set-up-centos-8-in-virtualbox/https://myblog.jszsoft.com/posts/2020-11-18-install-and-set-up-centos-8-in-virtualbox/End-to-end guide installing CentOS 8 in VirtualBox and configuring networking, Java 11, MySQL, MongoDB, Redis, Nginx, NodeJS and PM2.Wed, 18 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-17-set-up-webpack-for-mock-testing/https://myblog.jszsoft.com/posts/2020-11-17-set-up-webpack-for-mock-testing/Use connect-api-mocker and webpack dev-server proxy to mock or forward backend API calls so React UI development can proceed independently.Tue, 17 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-07-set-up-react-in-nodejs/https://myblog.jszsoft.com/posts/2020-11-07-set-up-react-in-nodejs/Combine a React frontend and NodeJS backend into a single server to avoid CORS, serving both static bundles and dynamic /api routes.Sat, 07 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-04-mathjs-and-plotlyjs-in-react/https://myblog.jszsoft.com/posts/2020-11-04-mathjs-and-plotlyjs-in-react/A small React demo that evaluates any f(x) with math.js and plots it with Plotly — plus the plain-HTML equivalent.Wed, 04 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-03-start-springboot-application-at-boot-time-in-centos-7/https://myblog.jszsoft.com/posts/2020-11-03-start-springboot-application-at-boot-time-in-centos-7/Create systemd service files with start/stop shell scripts so a Spring Boot scheduler job starts automatically on CentOS 7 reboot.Tue, 03 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-02-how-to-set-up-a-modded-minecraft-server/https://myblog.jszsoft.com/posts/2020-11-02-how-to-set-up-a-modded-minecraft-server/Step-by-step guide to install a Forge-based modded Minecraft server on Linux and Windows, including firewall port configuration.Mon, 02 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-11-01-hosting-a-web-server-at-home/https://myblog.jszsoft.com/posts/2020-11-01-hosting-a-web-server-at-home/Self-host a web server using a DDNS domain, router port forwarding, and a free Let's Encrypt TLS certificate for HTTPS.Sun, 01 Nov 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-10-28-passportjs-in-nodejs-handle-oauth2/https://myblog.jszsoft.com/posts/2020-10-28-passportjs-in-nodejs-handle-oauth2/How to configure PassportJS in a NodeJS backend to handle Google OAuth2 for both mobile and web clients, with routes and callback handling.Wed, 28 Oct 2020 12:00:00 GMThttps://myblog.jszsoft.com/posts/2020-10-26-hello-world-starting-my-react-blog-on-github-pages/https://myblog.jszsoft.com/posts/2020-10-26-hello-world-starting-my-react-blog-on-github-pages/Kickoff post: why I built this blog with React and Material-UI, hosted it on GitHub Pages, and a fun 12-balls weighing puzzle to start.Mon, 26 Oct 2020 12:00:00 GMT