Building things, breaking things, and everything in between
Write-ups of projects, hackathons, homelab experiments and whatever I'm figuring out in CS and life in general, by Rahul Vedant Pemsing.
"Life is a tragedy in close-up, and a comedy in long shot."
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My pre-first act as AWS club president was a disaster (and I learned a lot)
I represented the AWS Student Builder Group at Monash University Malaysia's first Tech Club Award Night and fumbled the presentation. Here's what went wrong and everything I'm fixing before 2027.
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FairSight revisited: the bias in my bias detector was twice what I claimed
A FIT1055 prototype that detects gender bias in hiring. Rerunning it showed women hired at 1.3% instead of the intended gap, and a "mitigation" that only works because we planted the bias ourselves.
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Rereading my pathfinding visualiser: A*, Dijkstra, and an RRT that never arrives
A first-year Streamlit project, benchmarked properly for the first time. A* checks 6× fewer cells than Dijkstra, the README describes the wrong heuristic, and RRT fails every time on a big grid.
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Putting three old projects back online with one Dockerfile
A roguelike, a pathfinding visualiser and FairSight, all Streamlit apps, now on my homelab under one deployment pattern. Plus a bug that only exists once a game is public.
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My "LAN speed test" was actually an internet speed test
I'd just replaced a faulty LAN cable, so when iperf3 said 30 Mbit/s I blamed the new one. The traffic had never touched the LAN.
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My new monitoring paged me twice on day one. Good.
A flaky HTTP/2 ping and a backup job that ran fine by hand but not under systemd. Both were real bugs, and both got caught.
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Getting a homelab ready to run for three months without me
No sleep, a watchdog, key-only SSH, a wiped HDD turned into storage and backups, a second way in, and an outside alarm for when the box goes dark.
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ExamX, part 2: cloud models, a public site, and pressing pause
Adding Gemini and Claude back ends, putting the app online behind a Cloudflare Tunnel, and deciding to stop and actually study.
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Auditing a gaming laptop that thinks it's a server
A read-only audit of my homelab box. No firewall, password SSH, no backups, and 86 unsafe shutdowns on the SSD.
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ExamX, part 1: a practice-exam generator that marks its own papers
One evening, five past papers and a 4 GB GPU. What worked, what the local models got wrong, and why the code ended up doing most of the marking.
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ShipDoc, part 2: moving off AWS before the account expired
The hackathon's AWS account ended on 18 October. ShipDoc moved to my homelab behind Caddy and a Cloudflare Tunnel, and the old domain now explains where it went.
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How an old gaming laptop became my homelab
A Lenovo Legion Y540, Arch Linux, SSH and Tailscale. How my "learn Linux" machine turned into the server that hosts my projects.
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ShipDoc, part 1: a perfect score locally, 0.9869 on Lambda
Our Averis × Monash Hackathon entry checks shipping documents. Getting it onto AWS was my job, and the cloud scored lower than my laptop for a reason I didn't expect.
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Anxin: two AI models, and what to do when only one answers
Team Tenners' entry for the MUBA Blockchain Hackathon, a bilingual scam checker on Gonka's decentralised inference network. It made the top 21 of its track.
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Planning errands is the travelling salesman problem in disguise
For the Monash × Shortcut Asia Internship Challenge I built a route planner. Exact answers for small trips, fast good-enough answers for big ones.
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Hello, world (again)
Why I'm starting a journal, and what you can expect to find here.