https://cozi.dev/Recent content on CoziHugo -- gohugo.ioen-usThu, 02 Jul 2026 14:00:00 +0700https://cozi.dev/posts/git-worktrees-parallel-claude-code/Thu, 02 Jul 2026 14:00:00 +0700https://cozi.dev/posts/git-worktrees-parallel-claude-code/You’re deep in a feature branch with Claude Code chewing through a refactor.https://cozi.dev/posts/mcp-connect-claude-to-your-tools/Wed, 01 Jul 2026 12:00:00 +0700https://cozi.dev/posts/mcp-connect-claude-to-your-tools/Here’s a workflow you’ve probably done a hundred times. You ask Claude to help with a bug.https://cozi.dev/posts/custom-slash-commands-claude-code/Mon, 15 Jun 2026 15:30:00 +0700https://cozi.dev/posts/custom-slash-commands-claude-code/There’s a prompt you type all the time. Maybe it’s “review this diff for security issues, focus on auth and input validation, ignore style nits.https://cozi.dev/posts/refactoring-go-with-claude-code/Mon, 15 Jun 2026 12:00:00 +0700https://cozi.dev/posts/refactoring-go-with-claude-code/Go code ages well, mostly. The language doesn’t change much, the standard library stays stable, and idiomatic Go from five years ago still looks fine today.https://cozi.dev/posts/plan-mode-make-claude-think-first/Fri, 12 Jun 2026 12:00:00 +0700https://cozi.dev/posts/plan-mode-make-claude-think-first/There’s a failure mode with AI coding tools that everyone recognizes: you describe a change, the model immediately starts editing files, and three minutes later you’re reverting half of it because it ran off in the wrong direction.https://cozi.dev/posts/subagents-stop-burning-your-context-window/Thu, 11 Jun 2026 12:00:00 +0700https://cozi.dev/posts/subagents-stop-burning-your-context-window/Here’s a pattern I kept hitting with Claude Code: I ask it to fix something, it goes off and reads fifteen files to figure out where the problem lives, and by the time it starts actually fixing things, half the context window is gone.https://cozi.dev/posts/claude-code-hooks-that-earn-their-keep/Wed, 10 Jun 2026 11:00:00 +0700https://cozi.dev/posts/claude-code-hooks-that-earn-their-keep/Most of what I tell Claude Code, I only have to say once and it sticks for the session.https://cozi.dev/posts/writing-a-claude-md-that-actually-helps/Tue, 09 Jun 2026 14:30:00 +0700https://cozi.dev/posts/writing-a-claude-md-that-actually-helps/Most CLAUDE.md files I see are either empty or a dumping ground.https://cozi.dev/posts/leveling-up-claude-code-with-superpowers/Tue, 09 Jun 2026 09:39:43 +0700https://cozi.dev/posts/leveling-up-claude-code-with-superpowers/A while back I wrote about spec-driven development with Spec Kit, which fixed the “the agent built the wrong thing” problem by making me write the spec before any code.https://cozi.dev/posts/spec-driven-development-with-github-spec-kit/Sun, 07 Jun 2026 22:00:00 +0700https://cozi.dev/posts/spec-driven-development-with-github-spec-kit/I have been using AI coding agents long enough to know the failure mode by heart.https://cozi.dev/posts/monitoring-and-distributed-tracing-with-grafana-prometheus-loki-and-tempo/Mon, 01 Dec 2025 11:34:20 +0700https://cozi.dev/posts/monitoring-and-distributed-tracing-with-grafana-prometheus-loki-and-tempo/Why I Built a Small Observability Stack Over the last few years, my systems have become more distributed: multiple services, containers, and external dependencies all talking to each other.https://cozi.dev/posts/serving-aws-s3-private-content-with-golang-and-aws-sdk-for-go-v2/Mon, 05 Feb 2024 22:08:46 -0600https://cozi.dev/posts/serving-aws-s3-private-content-with-golang-and-aws-sdk-for-go-v2/Have you ever wanted to serve private files from your AWS S3 storage to your users, but making the bucket public is not a safe option?https://cozi.dev/posts/setting-up-a-virtual-environment-with-vagrant-for-testing/Wed, 11 Oct 2023 02:31:18 -0500https://cozi.dev/posts/setting-up-a-virtual-environment-with-vagrant-for-testing/In the world of software development, testing is a critical aspect of ensuring the reliability and functionality of your applications.https://cozi.dev/posts/golang-create-combinations-from-n-arrays/Sat, 24 Sep 2022 20:31:26 +0700https://cozi.dev/posts/golang-create-combinations-from-n-arrays/This snippet is useful when you need create combinations from n arrays with picking one element from each array.https://cozi.dev/posts/mongodb-query-get-n-records-of-each-group-aggregation/Mon, 04 Jul 2022 16:16:38 +0700https://cozi.dev/posts/mongodb-query-get-n-records-of-each-group-aggregation/For example, you might want to get 5 members of each group in your application.https://cozi.dev/posts/transfer-files-to-new-server-using-ansible/Fri, 24 Jun 2022 22:11:23 +0700https://cozi.dev/posts/transfer-files-to-new-server-using-ansible/This is a simple Ansible playbook to use when I need to transfer files from the current server to a new server.https://cozi.dev/posts/advanced-go-custom-error-implement/Sat, 08 Jan 2022 09:39:12 +0700https://cozi.dev/posts/advanced-go-custom-error-implement/In the previous post, we have implemented our custom error:https://cozi.dev/posts/go-custom-error-implement/Sat, 01 Jan 2022 16:30:42 +0700https://cozi.dev/posts/go-custom-error-implement/Have you ever checked the error definition to see what it is?https://cozi.dev/posts/clean-disk-space/Fri, 10 Dec 2021 20:22:24 +0700https://cozi.dev/posts/clean-disk-space/Clean disk space You might run out of SSD space with your laptop or server.https://cozi.dev/posts/cozi-goes-dark/Sun, 21 Nov 2021 22:46:53 +0700https://cozi.dev/posts/cozi-goes-dark/Today, I decided to change cozi.dev to dark mode and I found out a quite awesome CSS property: color-scheme.https://cozi.dev/posts/how-to-use-multiple-ssh-keys-effectively/Sun, 10 Oct 2021 17:28:27 +0700https://cozi.dev/posts/how-to-use-multiple-ssh-keys-effectively/If you work on multiple projects, you might need to use multiple ssh key pairs for more security, right?https://cozi.dev/posts/building-golang-docker-image-for-production/Tue, 03 Aug 2021 10:19:05 +0700https://cozi.dev/posts/building-golang-docker-image-for-production/Today, we have modern applications and modern systems to manage and scale our containers.https://cozi.dev/posts/launching-informercat/Sun, 20 Jun 2021 20:59:59 +0700https://cozi.dev/posts/launching-informercat/Yes, my another new project informercat.com :) that I wanna share with you today which currently in BETA mode.https://cozi.dev/posts/prevent-multiple-webpack-instances-lazy-loading-conflict/Mon, 03 May 2021 14:51:48 +0700https://cozi.dev/posts/prevent-multiple-webpack-instances-lazy-loading-conflict/If you have been running multiple webpack instances with lazy loading, you must define the loading chunk function name in your webpack config.https://cozi.dev/posts/compile-pre-processors-to-css-for-runtime-uses/Sun, 14 Mar 2021 22:47:14 +0700https://cozi.dev/posts/compile-pre-processors-to-css-for-runtime-uses/In some cases, you might just want to compile your pre-processors styles like SCSS, LESS to CSS and assign it to a variable then do something with it at runtime.https://cozi.dev/posts/use-vue-dynamic-components-to-build-multiple-layouts-web-app/Sat, 06 Mar 2021 15:14:24 +0700https://cozi.dev/posts/use-vue-dynamic-components-to-build-multiple-layouts-web-app/This feature may not be used too much but it’s a useful and powerful feature of Vue.https://cozi.dev/posts/convert-html-to-json-data-structure-online/Sat, 30 Jan 2021 15:50:56 +0700https://cozi.dev/posts/convert-html-to-json-data-structure-online/Today, I will introduce a tool that help you to convert HTML to JSON data structure online:https://cozi.dev/posts/how-to-using-tailwind-css-2-with-vue-3/Wed, 30 Dec 2020 12:28:05 +0700https://cozi.dev/posts/how-to-using-tailwind-css-2-with-vue-3/I used to choose Bulma as CSS framework for my personal projects.https://cozi.dev/posts/how-to-archive-zero-downtime-deployments-in-kubernetes/Fri, 20 Nov 2020 05:21:53 +0700https://cozi.dev/posts/how-to-archive-zero-downtime-deployments-in-kubernetes/It was worse when you need to wait until late at night to deploy your app in production because you scare to break users’ experience when the short downtime happens after deployment.https://cozi.dev/posts/easy-way-to-get-started-with-vim-as-your-ide/Sat, 07 Nov 2020 10:57:34 +0700https://cozi.dev/posts/easy-way-to-get-started-with-vim-as-your-ide/You want to use Vim as your IDE, but don’t know how to get started?https://cozi.dev/posts/vue-cli-4-build-statics-for-an-existing-app-part-2/Fri, 23 Oct 2020 16:39:14 +0700https://cozi.dev/posts/vue-cli-4-build-statics-for-an-existing-app-part-2/In the previous part, we have updated Vue CLI config to output static files that we can manually inject to anywhere.https://cozi.dev/posts/gmob-go-mongodb-driver-document-builder/Sat, 03 Oct 2020 08:48:07 +0700https://cozi.dev/posts/gmob-go-mongodb-driver-document-builder/When I worked with Mongo Go Driver, it was complicate to make a search, or update query document(s) with dynamic conditions.https://cozi.dev/posts/launching-supics/Sun, 27 Sep 2020 10:24:15 +0700https://cozi.dev/posts/launching-supics/A few days ago, I launched supics.com which is my another side project that let people download/upload wallpapers for any devices.https://cozi.dev/posts/mongodb-filter-by-nested-object-field/Sun, 30 Aug 2020 21:21:50 +0700https://cozi.dev/posts/mongodb-filter-by-nested-object-field/Consider our logs collection contains with each document has a set of logItems, each item store sold status and price:https://cozi.dev/posts/automate-build-and-publish-docker-image-with-gitlab-ci/Sun, 02 Aug 2020 08:29:24 +0700https://cozi.dev/posts/automate-build-and-publish-docker-image-with-gitlab-ci/If you’re using GitLab then you have a free container registry for your projects.https://cozi.dev/posts/effective-testing-api-with-insomnia/Sat, 18 Jul 2020 10:44:34 +0700https://cozi.dev/posts/effective-testing-api-with-insomnia/Introduction If you are developer working with API then you may using Insomnia or Postman for testing them.https://cozi.dev/posts/debugging-go-http-server-with-vs-code/Sun, 28 Jun 2020 22:56:42 +0700https://cozi.dev/posts/debugging-go-http-server-with-vs-code/Like the title said, in this article we will do debugging go application with VS Code and Go extension.https://cozi.dev/posts/inject-vue-instance-into-an-iframe-that-create-in-runtime/Sun, 21 Jun 2020 22:59:16 +0700https://cozi.dev/posts/inject-vue-instance-into-an-iframe-that-create-in-runtime/Introduction Have you had ever wanted your component style won’t be affected by any third-party style and too lazy to create a new page to put it into iframe src?https://cozi.dev/posts/building-a-simple-microservices-using-go-micro-and-echo-frameworks/Wed, 10 Jun 2020 21:48:16 +0700https://cozi.dev/posts/building-a-simple-microservices-using-go-micro-and-echo-frameworks/Introduction In this article, we will learn how to build a simple microservices using Go Micro and Echo frameworks.https://cozi.dev/posts/vue-cli-4-build-statics-for-an-existing-app/Sat, 30 May 2020 09:24:20 +0700https://cozi.dev/posts/vue-cli-4-build-statics-for-an-existing-app/Introduction By default, Vue CLI build target is App which means your static will auto inject to a static index.https://cozi.dev/posts/moving-to-macos/Thu, 28 May 2020 21:33:52 +0700https://cozi.dev/posts/moving-to-macos/After several years of using Ubuntu laptop for programming, I have decided to upgrade my laptop 👨‍💻.https://cozi.dev/posts/simple-django-vue-websocket-chat-application-using-channels/Sun, 17 May 2020 14:17:27 +0700https://cozi.dev/posts/simple-django-vue-websocket-chat-application-using-channels/Introduction In this article, we will create a simple chat application using django, vue and channels.https://cozi.dev/posts/writing-simple-go-echo-websocket-test-recipe/Tue, 05 May 2020 22:37:57 +0700https://cozi.dev/posts/writing-simple-go-echo-websocket-test-recipe/Introduction Today, I’ll show you how I set up a simple test for WebSocket using gorilla/websocket in Echo framework and how it makes me more confident with my code 😄https://cozi.dev/posts/how-to-setup-drone-ci-for-github-using-ansible/Fri, 01 May 2020 06:57:22 +0700https://cozi.dev/posts/how-to-setup-drone-ci-for-github-using-ansible/Introduction This tutorial will show you how to set up Drone CI for GitHub using Ansible.https://cozi.dev/about/Mon, 01 Jan 0001 00:00:00 +0000https://cozi.dev/about/Hey, I’m Tung Quach Software engineer from Vietnam. I mostly do backend and cloud stuff - Go, distributed systems, and all the unglamorous plumbing that keeps services alive.https://cozi.dev/archives/Mon, 01 Jan 0001 00:00:00 +0000https://cozi.dev/archives/https://cozi.dev/hire-me/Mon, 01 Jan 0001 00:00:00 +0000https://cozi.dev/hire-me/Work with me I’m a backend-leaning full-stack engineer. I build APIs, services, and the cloud infra they run on - and I care just as much about whether it survives production as whether it looks good in a demo.https://cozi.dev/portfolio/Mon, 01 Jan 0001 00:00:00 +0000https://cozi.dev/portfolio/A mix of stuff I’m still building and projects I’ve since shelved.