Learning on Xiangtao's log

DesktopPet: A Desktop Pet I Built to Help Me Study in English

15989119660@163.com (Xiangtao XIAO) — Tue, 29 Sep 2026 00:00:00 +0800

A study companion that lives on the macOS desktop, with chat, word lookup, live captions and notes after class. This post covers the scope decisions, the model comparisons and a few things I learned along the way.

AI Agents, From Chatbot to Production

15989119660@163.com (Xiangtao XIAO) — Sat, 14 Mar 2026 00:00:00 +0000

AI Agents, From Chatbot to Production

An AI agent is the LLM application taken further — something that can plan on its own, carry out tasks, and interact with its environment.

Foundational papers:

Yao, S., et al. (2022). “ReAct: Synergizing Reasoning and Acting in Language Models.” ICLR. [paper] — the ReAct framework, the core pattern behind most agents
Wei, J., et al. (2022). “Chain-of-Thought Prompting Elicits Reasoning in Large Language Models.” NeurIPS. [paper]
Wang, G., et al. (2024). “A Survey on Large Language Model based Autonomous Agents.” arXiv. [paper] — a survey of the agent landscape

1. The Overall Progression

Chatbot → Tool Use → Agent → Production Agent

What each stage means:

Prompt Engineering

15989119660@163.com (Xiangtao XIAO) — Thu, 12 Mar 2026 00:00:00 +0000

Prompt Engineering

https://www.coursera.org/learn/chatgpt-prompt-engineering-for-developers-project/home/welcome

Prompt engineering is the practice of designing and refining the input you give a large language model so it produces the output you actually want. It took off after GPT-3 came out, and it’s basically the bridge between what a user wants and what the model can do.

Key papers:

Brown, T. B., et al. (2020). “Language Models are Few-Shot Learners.” NeurIPS. [link] — the GPT-3 paper, the first to really demonstrate the potential of prompt engineering
Wei, J., et al. (2022). “Chain-of-Thought Prompting Elicits Reasoning in Large Language Models.” NeurIPS. [link]

1. Prompting Principles

Principle 1: Write clear and specific instructions

Clarity and specificity are the two things that matter most when writing a prompt. Vague instructions tend to produce unpredictable outputs, while specific ones noticeably improve output quality.

RAG (Retrieval-Augmented Generation)

15989119660@163.com (Xiangtao XIAO) — Sun, 08 Mar 2026 00:00:00 +0000

RAG

RAG (Retrieval-Augmented Generation) combines information retrieval with text generation — it pulls in an external knowledge base to make an LLM’s answers better.

Foundational papers:

Lewis, P., et al. (2020). “Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks.” NeurIPS. [paper] — the paper that started RAG
Guu, K., et al. (2020). “REALM: Retrieval-Augmented Language Model Pre-Training.” ICML. [paper]
Izacard, G., & Grave, É. (2021). “Leveraging Passage Retrieval with Generative Models for Open Domain Question Answering.” EACL. [paper] — a different take on RAG

1. Context Window

What it is

The context window is the maximum amount of text an LLM can read and reason over in a single pass.

Understanding the Transformer, From a Product Manager's Angle

15989119660@163.com (Xiangtao XIAO) — Fri, 20 Feb 2026 00:00:00 +0000

The Transformer reshaped NLP and became the backbone of every modern LLM. This post walks through its core ideas from a product perspective.

A Tour of Payment Methods on Chinese E-Commerce Platforms

15989119660@163.com (Xiangtao XIAO) — Thu, 29 Jan 2026 00:00:00 +0000

1. Comparing the mainstream payment methods

1. Business-to-business cash transfer

How it works: an initiated transfer from a bank counter or corporate online banking, or a payment through a bank’s fund-splitting system with a receipt.

Limits: large transfers are possible. Anything above RMB 50,000 goes through the PBOC’s large-value payment system, which doesn’t run on weekends and holidays, and can be affected accordingly (on weekdays it runs from 20:30 the previous evening through 17:15 the same day).

A First Look at Cross-Border Payments

15989119660@163.com (Xiangtao XIAO) — Fri, 05 May 2023 00:00:00 +0000

Notes from working through Cross-Border E-Commerce Payment and Settlement, my starting point for getting into cross-border payments.

A few basic concepts

Foreign exchange (FX)

Foreign exchange is a claim held by a country’s monetary authorities — the central bank, currency management bodies, exchange stabilization funds, and the treasury — in the form of bank deposits, treasury bills, and short- and long-term government securities, that can be drawn on to cover a balance-of-payments deficit. It covers foreign currency itself, foreign-currency deposits, foreign-currency securities (government bonds, treasury bills, corporate bonds, stocks), and foreign-currency payment instruments such as drafts, bank certificates of deposit, and postal savings certificates.

What I'd Tell a New Product Manager on Day One

15989119660@163.com (Xiangtao XIAO) — Fri, 30 Jul 2021 00:00:00 +0000

Wrapping up what to prepare for when you’re new to a job, and the mistakes I made so I don’t forget them.

1. Get your tools set up

Find out what software the company runs on day to day. If IT already has it installed for you, great. If it’s something you’ve never used, learn the basics when you have a spare moment, or just ask a colleague.

2. Learn how the place actually works

Notes on Requirement Analysis and Management

15989119660@163.com (Xiangtao XIAO) — Tue, 30 Mar 2021 00:00:00 +0000

When you’re digging into what users actually need, it’s rarely something concrete and explicit. There’s the old Ford line — “if I’d asked people what they wanted, they’d have said a faster horse” — but once you get to actually building the product, you still have to land on something concrete: specific features that satisfy the underlying need. So what I mean by “requirement analysis and management” here is the whole chain: start from a surface-level ask, dig into the real need underneath it, evaluate it, land on a specific solution, and hand that off to engineers and designers to turn into an actual product. B2B and B2C products differ quite a bit in how this plays out.

Notes on Doing Competitive Analysis

15989119660@163.com (Xiangtao XIAO) — Sun, 28 Mar 2021 00:00:00 +0000

1 Why Bother with Competitive Analysis

1. Better decisions. Understanding competitors’ products helps you position your own — and steer clear of the strongest players so you don’t wander into a red ocean. It lowers the risk of getting your bets wrong.

2. Learning from others. Studying what makes a competitor’s product strong lets you build more deliberately: take what works, absorb their strengths, and use it to sharpen your own edge.