Peifeng Wang — Full-Stack Engineer, Tokyo

2026.07.27TECH

Rebuilding My Personal Site, Part II: A Theme System That Breathes with Time

The previous post was about merging three disconnected websites into one and designing four distinct visual themes. This second entry revisits the…

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2026.07.27

Rebuilding My Personal Site, Part II: A Theme System That Breathes with Time

The previous post was about merging three disconnected websites into one and designing four distinct visual themes. This second entry revisits the…

TECH→

2026.07.06TECH

I Built Another Japanese Vocabulary Puzzle Game — Kotoba Puzzle

After building Kotoba, I created Kotoba Puzzle to explore a more playful way of reviewing Japanese vocabulary through kana tracing, meanings, and…

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2026.07.06

I Built Another Japanese Vocabulary Puzzle Game — Kotoba Puzzle

After building Kotoba, I created Kotoba Puzzle to explore a more playful way of reviewing Japanese vocabulary through kana tracing, meanings, and…

TECH→

2026.06.21TECH

I Built a Simple Japanese Vocabulary Tool for Myself — Kotoba

I built Kotoba for my own Japanese study—a lightweight JLPT vocabulary trainer with N5–N1 word learning, daily challenges, mistake review, local…

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2026.06.21

I Built a Simple Japanese Vocabulary Tool for Myself — Kotoba

I built Kotoba for my own Japanese study—a lightweight JLPT vocabulary trainer with N5–N1 word learning, daily challenges, mistake review, local…

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2026.06.10LIFE

What 12 Years Across China and Japan Taught Me About Where Engineers Actually Grow

12 years as an engineer across China and Japan taught me one thing: what makes you remember a company is never the tech stack. It's the small things…

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2026.06.10

What 12 Years Across China and Japan Taught Me About Where Engineers Actually Grow

12 years as an engineer across China and Japan taught me one thing: what makes you remember a company is never the tech stack. It's the small things…

LIFE→

2026.05.10TECH

Sky Finance Series #1: From POC to a Systematic RAG Platform — Architecture Overview

I rebuilt and open-sourced Sky Finance — this post is the first in a series documenting the project. It covers the overall architecture, the core…

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2026.05.10

Sky Finance Series #1: From POC to a Systematic RAG Platform — Architecture Overview

I rebuilt and open-sourced Sky Finance — this post is the first in a series documenting the project. It covers the overall architecture, the core…

TECH→

2026.05.09TECH

Rebuilding My Personal Site: Cyber, Sakura & Pixels

I rebuilt my personal site into a unified experience with four distinct themes — a Vim-inspired dark terminal, a clean light mode, a Sakura · Fuji…

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2026.05.09

Rebuilding My Personal Site: Cyber, Sakura & Pixels

I rebuilt my personal site into a unified experience with four distinct themes — a Vim-inspired dark terminal, a clean light mode, a Sakura · Fuji…

TECH→

2026.04.05TECH

SkyFinance POC: I Built a Personal Stock Alert System with Local LLMs and Cloud AI

I hold positions across two markets — US equities (NVDA, CRWD, PLTR, COIN) and Tokyo-listed stocks (7011.T Mitsubishi Heavy, 6758.T Sony, 6367.T…

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2026.04.05

SkyFinance POC: I Built a Personal Stock Alert System with Local LLMs and Cloud AI

I hold positions across two markets — US equities (NVDA, CRWD, PLTR, COIN) and Tokyo-listed stocks (7011.T Mitsubishi Heavy, 6758.T Sony, 6367.T…

TECH→

2026.03.14TECH

SkyRss: I Built a Daily News Pipeline with Local LLM + RSS

The first post covered SkyAgenda — a morning briefing agent that wires together Apple Calendar, weather forecasts, and a locally-running LLM. This…

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2026.03.14

SkyRss: I Built a Daily News Pipeline with Local LLM + RSS

The first post covered SkyAgenda — a morning briefing agent that wires together Apple Calendar, weather forecasts, and a locally-running LLM. This…

TECH→

2026.03.07TECH

SkyAgenda: Building a Privacy-First Daily Briefing Agent with a Local LLM

I spent the last few days building SkyAgenda — a local automation agent that reads my Apple Calendar, fetches weather forecasts for upcoming event…

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2026.03.07

SkyAgenda: Building a Privacy-First Daily Briefing Agent with a Local LLM

I spent the last few days building SkyAgenda — a local automation agent that reads my Apple Calendar, fetches weather forecasts for upcoming event…

TECH→