# Weekly Dev Log 2026-W13 > Source: > Published: 2026-07-10 21:08:52+00:00 ## 🗓️ This Week - This week, I mainly focused on **iOS development**📱. - I also tested a small workflow using Codex: organizing ideas, creating a design file, and implementing a SwiftUI prototype. Through that process, I realized that **Codex can be very helpful for making iOS development more efficient**💡. - **Until now, I had been using Codex in a rather ad hoc way**, sending instructions only when I wanted it to handle a specific task😂. - This week, I started thinking about **how to make that workflow more efficient, and how to make Codex act more like a development partner** that understands the project in the same way I do🧐. - As I explored this, I realized that **I needed to review my Codex settings, build better rule files for giving instructions to Codex, and rethink how I use Codex in my own workflow**🛠️. - Working through all of this slightly changed **the way I think about AI agents**🤖. ## 📱 iOS (SwiftUI) - I organized the UI structure for ToneDrill mini in Figma. - I created a structured design page and a small Mini Design System in Figma. - I summarized colors, typography, buttons, fretboard parts, spacing, and radius rules. - I updated the implementation note so Codex could understand the design direction. - I asked Codex to implement the SwiftUI fretboard UI based on the Figma design and implementation note. - I changed the instruction so app colors would be managed as Color Sets in `Assets.xcassets` . - I reviewed the SwiftUI code for ToneDrill implemented by Codex. - I asked Codex questions to better understand the implementation. - I checked how the fretboard UI is drawn and updated in SwiftUI. ## 🆙 Updating my workflow ### 🤖 AI agent workflow - I worked on setting up a more structured workflow for using Codex in my development projects. - I created **a global **`AGENTS.md` file for Codex (`~/.codex/AGENTS.md` ). - I created **a project-level **`AGENTS.md` file at the root of the repository (`repo-root/AGENTS.md` ). - I separated the responsibilities of the global `AGENTS.md` file and the project-level `AGENTS.md` file. - I created `docs/codex/TaskIndex.md` as a task management document. In it, I organized both immediate tasks and mid- to long-term tasks, and defined a consistent format for writing them down. - To reduce the need to repeatedly explain the project background, past work, and current tasks every time I move to a new chat, I decided to **build a workflow and create a mid- to long-term project memory in Notion** for the work and lessons I develop with Codex. - I created a Notion page called `AI Operating Manual` so **AI can summarize the project overview, what I learned, mistakes, improvements, fixes**, and any rules that should be added to the project-level `AGENTS.md` . I connected it through **Notion MCP** so Codex can update it. - I organized this entire process as a workflow. - At the start of a chat, Codex should read the `AI Operating Manual` Notion page, then read `AGENTS.md` and `TaskIndex.md` , so it can start working with the same understanding as me. I registered this as a Skill so I can call it with a single phrase. - At the end of a work session, Codex should summarize what was done and organize what should be saved as mid- to long-term project memory in the `AI Operating Manual` Notion page. I registered this as another Skill so I can call it with a single phrase. - Finally, I registered a separate Skill that can write the summarized content to the `AI Operating Manual` Notion page. I separated this from the summary Skill so that I can review the content first and decide what should actually be saved as mid- to long-term project memory before running the write operation. # 💡 Key Takeaways ## 📱 SwiftUI Learning - **By asking Codex to implement the SwiftUI UI based on the Figma UI structure and the small design system page**, I was able to **get a UI that was very close to the design I created in Figma**. - I learned that **Codex sometimes adds many custom style definitions in the code**, even in areas where SwiftUI’s default styling system would be enough. I need to decide more carefully which parts should rely on **SwiftUI’s default styles** and which parts should be customized. - Through this implementation, I learned that I need to **separate the parts where I want to take advantage of SwiftUI’s built-in default styles from the parts where I want to apply my own custom design**. - I also noticed that **Codex tends to implement SwiftUI previews using older syntax**. This helped me understand the difference between older preview code and the newer style I learned in the SwiftUI tutorials. - I also learned that if I want colors to be managed in `Assets.xcassets` , I need to explicitly tell Codex to do that. - I learned that I should add rules for Codex so that the same kind of issue does not happen in the next implementation. - I learned how SwiftUI draws horizontal and vertical lines using `.frame(width:height:)` and `.position(x:y:)` . - I learned that `.position(x:y:)` places the center of a view. - I learned that a parent view’s `@State` change causes SwiftUI to recalculate the parent view’s body. - I learned that child views are updated when new values are passed from the parent view. - I learned that `@ViewBuilder` does not trigger UI updates by itself. - `@ViewBuilder` is used to write conditional view logic, such as showing or hiding a view depending on a condition. ## 🆙 Updating my workflow Learning ### 🤖 AI agent workflow #### 🐛 How My Workflow Changed - Previously, I had to explain in each prompt who I am, how I prefer to work, and what kind of reasoning I expect from Codex. For example, I often had to explain my background and say things like, “Because I think this way, please do not do that.” By organizing this information in advance, **I no longer need to repeat those explanations every time, and the direction of Codex’s responses is now much closer to what I expect**. - I can now **start talking with Codex about the task I want to work on right away, without wasting time aligning the process**. Before, when I felt that Codex was moving in a slightly different direction, I had to explain the project background, current progress, and what I wanted to do next in order to bring Codex back to the same understanding. - By formatting the workflow, **I no longer feel unsure about what information I should give Codex when working on any project**. I created a system that lets Codex reach a consistent level of understanding with a minimal prompt. Because I also defined a clear way to operate Codex in order to protect that system, I feel that I can work with it more confidently and without hesitation. #### 📝 What I Learned From This - I felt that **in order to use an AI agent effectively**, I need to **clearly tell it who I am and what kinds of actions or workflows I prefer**. - At the same time, I realized that **this kind of workflow becomes possible when I clearly define what I will delegate to the AI agent and what I will handle myself**. In my workflow, the AI agent should not immediately start working on a task. Instead, it should first propose a plan, and then I, as the human user, review and approve it before the task is executed. - This feels **similar to the relationship between a manager and a team member**. In other words, I felt that **using an AI agent effectively depends on how well the human can act as a capable manager**. I also realized that **the skills used to manage work in real-world teams can be useful when working with AI agents**. - **For regular applications that are used simply as tools**, **the important skills are things like understanding the features** and knowing how to use the application well. - **I found it interesting that the skills needed for AI agents are different** from the skills needed for ordinary tools. This difference feels like one of the unique characteristics of AI agents. # 🚀 Next Week - Continue developing the top menu screen for ToneDrill. - Organize the UI adjustment points for the portfolio site implemented by Codex in Notion, then start making small UI refinements. - Continue working on the AI Security Learning Path. # 🌈 Goals for This Year ## 📱 iOS (SwiftUI) - Build a solid foundation in SwiftUI and create at least one iOS app. ## 🌐 Web Development - Continue posting learning logs on Dev.to and eventually turn them into a portfolio site using React Router v7. ## 🔐 Security (TryHackMe) - Continue learning cybersecurity on TryHackMe.