I’m Jiangwei Chong, a software engineer based in Singapore. I’ve spent years building and optimising financial and fintech software processing many millions of dollars of transactions. Here I write mostly for myself in the domains of computer science, mathematics, and finance.
Besides the timestamped blog posts, I’ve also written the following standalone documents:
- HLPR • Half-Life Physics Reference – an attempt to document the Half-Life game physics for speedrunning.
Drop me an email at jw@linearspace.io.
Posts
Oct 5, 2025
Syfe's embarrassingly misleading fee comparison
How Syfe makes unfair and highly misleading fee comparison vs DIY investing.
Oct 1, 2025
How much does your investment grow after contributions?
Equations for computing how much your investment is worth in the future, with rigorous proofs.
Aug 28, 2025
What do you get out of CPF LIFE?
Reverse engineering the maths behind CPF LIFE payouts.
Aug 26, 2025
Should you donate to "earn" tax relief?
Donate money to reduce tax: do you actually pay less?
Aug 22, 2025
AES(AES(AES(...))): What happens if you keep encrypting?
What value do you end up?
Aug 16, 2025
When 0% interest isn’t.
Aug 14, 2025
How do mortgage calculators work?
Mortgage maths with huge consequences.
Apr 26, 2021
How hornets can fly through walls in Half-Life.
Mar 12, 2021
You run slower and jump lower when you’re tired in CS1.6!
Mar 6, 2021
Why do dead bodies block you in Half-Life?
Mar 1, 2021
Opposing Force’s crowbar.
Feb 13, 2021
Why only human grunts duplicate ammo drops
If only we get to do this with other NPCs…