Tech on Armstrong Yan

Why Sharing Myinfo Is More Than Autofill

Sun, 21 Jun 2026 18:34:32 +0800

A form asks for your name, address, nationality, contact details, income information, or family records. You have filled in some version of this form before. The service may also ask for documents, then someone or some backend process has to verify that the documents match what you typed.

Then a button appears:

Retrieve Myinfo

From the user’s point of view, this looks like autofill.

That is true, but incomplete. Autofill saves typing. Myinfo does something more important:

What Happens When You Scan a Singpass QR Code

Sun, 21 Jun 2026 18:33:32 +0800

You open a banking website on your laptop.

You click “Log in with Singpass”.

A QR code appears.

You open the Singpass app, scan the code, check the service name, approve the login, and the website suddenly knows it can let you in.

From the user’s point of view, the whole thing feels almost too simple. The QR code appears, the phone approves, the browser continues.

But the important question is:

Why Singpass Becomes National Trust Infrastructure

Sun, 21 Jun 2026 18:32:34 +0800

At first glance, Singpass looks like a login system.

You open a government website, click “Log in with Singpass”, scan a QR code, approve it on your phone, and continue. From the user’s point of view, the experience is simple. It feels like a national version of “Sign in with Google”.

But if we design such a system from first principles, it quickly becomes clear that login is only the visible tip of the system.

A Podcast Summarizer Taught Me That Summaries Are Not Understanding

Wed, 10 Jun 2026 15:43:19 +0800

Someone asked me a simple question about a project on my resume:

Did this software actually solve your problem?

It was a good question.

The project was a podcast summarizer.

The source code is public here: yanqian/podcast-summarizer.

The original idea was straightforward.

Long audio is expensive to consume.

If I could transcribe it, summarize it, and read the summary, then maybe I could understand the whole episode without spending an hour listening.

I Built a Small Harness to Stop AI Coding Projects From Forgetting State

Thu, 04 Jun 2026 10:46:50 +0800

AI coding agents are powerful.

But long-running AI coding projects break in a very specific way:

the session is interrupted
the context becomes too long
the weekly quota runs out
tomorrow’s agent forgets yesterday’s decisions
the agent changes unrelated files
the agent marks work done too early

The problem is not that AI cannot write code.

The problem is that AI coding projects often do not have durable project state.

AI-Native Software Engineering, Part 1: Mental Models in Agentic Coding

Sat, 23 May 2026 20:33:47 +0800

AI can generate code. Harnesses can validate behavior. But who builds understanding?

This is Part 1 of the AI-Native Software Engineering series.

The series asks a larger question:

When AI lowers the cost of implementation,
what remains scarce in software engineering?

This article starts with the first scarce resource:

Understanding.

Over the past few months, I’ve been experimenting heavily with AI-assisted software development.

Not autocomplete.

Not AI as a coding copilot.

AI-Native Software Engineering, Part 2: Harness Engineering and Correctness

Sat, 23 May 2026 20:33:47 +0800

Why the most important part of AI-native software engineering may not be generation, but constraint.

This is Part 2 of the AI-Native Software Engineering series.

It continues from AI-Native Software Engineering, Part 1: Mental Models in Agentic Coding.

The previous question was:

If understanding no longer comes mainly from writing code,
how do humans build mental models in an agentic workflow?

The next question is:

If implementation is delegated,
where does correctness come from?

The conversation around AI-assisted software development often focuses on one thing:

AI-Native Software Engineering, Part 3: Software as Search

Sat, 23 May 2026 20:33:47 +0800

When implementation becomes abundant, engineering starts to look less like construction and more like navigation.

This is Part 3 of the AI-Native Software Engineering series.

It continues from AI-Native Software Engineering, Part 2: Harness Engineering and Correctness.

The first article asked:

How does understanding form when implementation is delegated?

The second article asked:

How does correctness form when generation is cheap?

This article asks:

If implementation keeps getting cheaper,
what are engineers actually doing?

Here, constraints shift meaning.

AI-Native Software Engineering, Part 4: Human Judgment Against Vibe Coding

Sat, 23 May 2026 20:33:47 +0800

You can automate implementation. You can automate evaluation. But judgment remains stubbornly human.

This is Part 4 of the AI-Native Software Engineering series.

It continues from AI-Native Software Engineering, Part 3: Software as Search.

The first article asked how understanding forms.

The second asked how correctness forms.

The third argued that software is starting to look like search.

This article pushes back on a dangerous misunderstanding:

If we have agents, harnesses, and constraints,
software can produce itself.

That is not true.

Understanding Singapore's Payment Stack: From Bank Apps to SGQR, PayNow, FAST, Contactless, and NETS

Mon, 11 May 2026 00:00:00 +0000

If you live in Singapore, you probably use these payment methods every day:

You send money to a friend via PayNow.
You scan a QR code at a hawker stall.
You tap your card or phone at a supermarket.
You use NETS at a local merchant.

They look similar from the user side, but underneath they solve different problems.

Tech on Armstrong Yan

Why Sharing Myinfo Is More Than Autofill

What Happens When You Scan a Singpass QR Code

Why Singpass Becomes National Trust Infrastructure

A Podcast Summarizer Taught Me That Summaries Are Not Understanding

I Built a Small Harness to Stop AI Coding Projects From Forgetting State

AI-Native Software Engineering, Part 1: Mental Models in Agentic Coding

AI-Native Software Engineering, Part 2: Harness Engineering and Correctness

AI-Native Software Engineering, Part 3: Software as Search

AI-Native Software Engineering, Part 4: Human Judgment Against Vibe Coding

Understanding Singapore's Payment Stack: From Bank Apps to SGQR, PayNow, FAST, Contactless, and NETS

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