Turning curiosity into code

Simulations, tools, and experiments across physics, biology, finance, political science, religion, and AI. Built in the open, mostly vibe-coded with Claude.

By small and simple things are great things brought to pass.
— Alma 37:6
Back to posts
Feb 26, 2026 · meta

Hello, World

This is the first post on a9l.im — a quick tour of the blog and a test of every markdown feature the parser supports.

Why a blog?

Building interactive simulations generates a lot of interesting problems — numerical precision, rendering tricks, algorithmic trade-offs. A blog is a good place to write them up.

What the parser handles

Text formatting

You can write bold, italic, and bold italic text. Inline code works too.

Here's a link to the repo and an image:

Placeholder

Lists

Unordered:

  • Zero dependencies
  • Vanilla JS only
  • No build step

Ordered:

  1. Write a markdown file
  2. Add it to posts.json
  3. Deploy

Blockquotes

The purpose of computation is insight, not numbers. — Richard Hamming

Code blocks

function greet(name) {
  return `Hello, ${name}!`;
}

console.log(greet('world'));

Horizontal rules

That covers all the basics. More posts to come.

Get in touch

I'm looking for collaborators first, users second. If you want to build something together — a sim, a tool, a weird research thing — email is the fastest way to me.

I build things to understand how things work.

I'm a9lim. Born in Palo Alto, raised in Singapore, college in San Diego — third culture kid by way of an international school education. Singapore isn't quite home, but it's the closest thing I have to one.

My interests run uncomfortably wide: physics, biology, finance, geopolitics, religion, AI, music. The throughline is that I'm drawn to systems and structure, and to the unifying narratives that hold a field together. ZFC. The Standard Model Lagrangian. Black–Scholes. The Whig theory of history. Different subjects, same shape — a small set of axioms doing a lot of work.

I got into building as a kid clicking around Colorado Boulder's PhET sims for hours at a time. Learned a frankly unreasonable amount of science by dragging sliders, and decided fairly early that letting people touch a thing is the best way to teach it. The simulations on this site are an attempt to pay that forward.

In high school I started building seriously: a physics engine that would eventually become Geon, an SIR–with–zombies epidemiology sim, an Asteroids clone with special relativity. Then I spent four years at UCSD getting a math degree, which I mostly coasted through. Things picked up again in late 2025 and I've been shipping ever since.

On vibe–coding

Almost everything here is built with Claude. I steer, Claude writes, we iterate until it works. I'm loud about this because I think it's the future and I want other people to feel licensed to try it. I've learned as much about code from reading what Claude writes as I would have writing it myself, and the productivity ceiling is somewhere I haven't found yet. If you have a thing you want to build, build it. The tools are here.

Currently

Reading David Chalmers on mechanistic interpretability — he dropped a paper recently that's been rattling around in my head. Betting AGI by end of 2027; if I had to wager, the Anthropic mythos is one or two model generations out. Listening to garage punk. Thinking about how to make scripture more navigable.

Other things, in no particular order

  • I have an academic obsession with the LDS faith and its history — same energy as someone obsessed with Gnosticism. The scripture project on this site is comparative religion, not devotional.
  • I once built a conlang called dung'amyon — a Sinitic / Sino–Xenic Esperanto based on simplified Middle Chinese. Got semi–fluent in it. The repo got deleted at some point, which I'm choosing to be relaxed about.
  • I don't get along with everyone, and I've made peace with that. I hold opinions strongly and update them readily when someone gives me a real argument. I act idiosyncratically — some people vibe with that, most don't. Both groups are correct.
  • The handle is the front of my UCSD email username. I kept it because it rolls off the tongue, and because the lim is satisfyingly Singaporean.

a9lim

Singapore mx@a9l.im github.com/a9lim @_a9lim @a9lim (Discord)

Profile

Independent developer building interactive educational simulations and browser tools at a9l.im. Specialized in zero–dependency, no–build web apps shipped collaboratively with agentic AI. Open to freelance and collaboration on DIY–flavored work — research tools, simulations, and browser experiments.

Experience

Independent Developer — a9l.im

Feb 2026 – Present
  • Built and maintain a portfolio of open–source interactive simulations and tools (see Selected Projects below) plus the shared design system and component library used across all of them — vanilla JavaScript, no frameworks, no build pipeline, no transpiler.
  • Architected the SSR layer on Cloudflare Workers + Assets: per–route HTMLRewriter injection, edge–rendered markdown, structured data, per–route security headers, and Analytics Engine logging.
  • Maintains the entire stack solo, infrastructure to typography, in collaboration with Claude.

SDDM Theme Maintainer — Catppuccin

2025 – Present
  • Led rewrite and modernization of Catppuccin's SDDM display manager theme in QtQuick.
  • Implemented dynamic accent color and per–user icon integration.
  • Automated theme generation across the four Catppuccin flavors to streamline maintenance.
  • Designed vector backgrounds and user iconography.

Selected Projects

Saklas

PyPI · Python
  • Activation steering and trait monitoring for HuggingFace transformers — extracts contrastive steering vectors and adds them to hidden states at generation time, no fine–tuning required.
  • Three interfaces: a terminal UI with live alpha knobs and probe sparklines, an HTTP server speaking both OpenAI /v1/* and Ollama /api/* wire formats on the same port, and a Python API for scripted experiments.
  • Ships 21 pre–built probes scoring affect, epistemic stance, register, and alignment in–flight; tested on Qwen, Gemma, Ministral, gpt–oss, Llama, and GLM.
  • Implements the contrastive–PCA reading procedure from Zou et al. (2023); published to PyPI under AGPL–3.0 with CI, type checking, and llama.cpp GGUF interchange.

Geon — Relativistic Particle Physics

JavaScript · WebGPU
  • Real–time N–body simulator running on WebGPU compute shaders, modeling 11 force types — Newtonian gravity, gravitomagnetism, Coulomb, Lorentz, Yukawa, Higgs and axion field couplings, Hubble expansion, 1PN general–relativistic corrections, spin–orbit, and radiation reaction.
  • Barnes–Hut tree acceleration for O(N log N) scaling; Boris integrator preserving phase–space volume.
  • Black–hole mode with Kerr–Newman event horizons, Hawking radiation, Schwinger pair–production discharge, and superradiant axion clouds. Nineteen curated presets demonstrate Keplerian orbits, Rutherford scattering, Higgs wells, gravitational–wave inspiral, and more.

Cyano — Cellular Metabolism

JavaScript
  • Interactive biochemistry simulator covering twelve metabolic pathways — glycolysis, gluconeogenesis, PPP, Krebs, beta–oxidation, fatty acid synthesis, the Calvin cycle, the light reactions, fermentation, the urea cycle, and amino acid catabolism — connected through shared metabolite pools.
  • 14–complex electron transport chain with proton motive force, oxidative phosphorylation, uncoupling, leak, and reactive oxygen species generation; allosteric regulation gates every reaction (PFK, PDH, ICDH).
  • Six organism presets including a cancer–cell preset that demonstrates the Warburg effect.

Shoals — Options Trading

JavaScript
  • Derivatives pricing simulator combining Heston stochastic volatility and Merton jump diffusion with a Vasicek mean–reverting interest rate. American options priced via 128–step Cox–Ross–Rubinstein binomial tree with term–structure volatility, moneyness skew, and discrete dividends.
  • 25–strike options chain with real–time Greeks, multi–leg strategy builder (spreads, straddles, condors, butterflies), payoff diagrams, and portfolio–level margin tracking.
  • Narrative event engine with 400+ curated scenarios — earnings, monetary policy, geopolitics, sector rotation, technical signals, black swans — chained via a Poisson scheduler with trait–aware likelihood weighting.

Gerry — Redistricting & Electoral Fairness

JavaScript
  • Interactive gerrymandering simulator on a procedural hex–tile electorate. Players paint districts and evaluate them against six fairness metrics: efficiency gap, partisan symmetry, competitive–district count, Polsby–Popper compactness, contiguity, and majority–minority districts.
  • Automated modes include pack–and–crack and a simulated–annealing fair–draw optimizer; Monte Carlo election stress tests run thousands of simulated elections with turnout noise to evaluate map robustness.
  • Procedural maps generated via seeded Perlin noise with configurable urban clustering and minority density, reproducible by URL hash.

Scripture — Sacred Text Reader

JavaScript
  • Browser–based reader for sixteen sacred texts spanning Christian, Islamic, LDS, Confucian, Taoist, Shinto, Zoroastrian, Buddhist, Finnish, and Norse traditions — ~50 MB of static JSON, loaded on demand per chapter.
  • Full–text search across all sixteen works, TF–IDF concordance for related passage discovery, verse–linked notes, text–to–speech, and deep linking to any verse via URL.
  • Edge–SSR'd verse content with per–chapter Chapter JSON–LD and per–verse Quotation structured data so the corpus is crawlable without JavaScript execution.

Education

University of California, San Diego

March 2026

B.S. in Mathematics · GPA 3.75 · GRE 335 (170Q, 165V)

Singapore American School

Class of 2023

Summa Cum Laude · GPA 4.50

Skills

Building with agentic AI
Daily driver: Claude Code. Comfortable directing, reviewing, and integrating large volumes of AI–generated code at production scale.
Languages
JavaScript (vanilla, ES modules, Canvas, WebGL, GLSL), Python (NumPy, Matplotlib, ML tooling), Java, QtQuick / QML, LaTeX, HTML, CSS.
Web & infrastructure
Cloudflare Workers, Workers Assets, Analytics Engine, edge SSR via HTMLRewriter, structured data (JSON–LD, schema.org, OpenGraph), self–hosted typography, no–build pipelines.
Other
Technical writing, vector graphics, soldering, Spanish (novice), conlang construction.

Open to

Freelance and collaborations — sims, tools, research–flavored DIY work. Reach out at mx@a9l.im.