Tag
#engineering-logs
9 articles
Articles tagged #engineering-logs
01A Library That Fits on a USB Stick
Wikipedia can work with no internet at all. A plain-language story of how offline Wikipedia reaches schools and clinics, why choosing the articles is the hard part, and what building OfflineShelf taught me about lists, change and giving credit.
6 minThe Engineering Logs
02I Invented 14 People to Break My University Website
A plain-language story about testing a university admissions website with fourteen imaginary people, from a careless applicant to a would-be hacker, and the real bugs they found that I never would have.
7 minThe Engineering Logs
03AIT: Building a University Admissions Portal From Scratch
How I turned what I learned in my XCL Technologies internship into Ahmer Institute of Technology: a university website with applicant, student, teacher, staff and admin portals, safe file uploads, Docker, and 58 end-to-end tests that found real bugs.
8 minThe Engineering Logs
04The Day the Money Moves
When you buy a share, you don't own it the moment you click. A plain-language story of trade settlement, T+1 and T+2, why holidays in two countries can push a payment back a day, and what building MarketClock taught me about dates that have a history.
4 minThe Engineering Logs
05The Weekend Is Not a Constant
Why 'is this a working day?' breaks so much software: weekends that differ by country and change over time, holidays that follow the moon, time zones that disagree about today, and the habits that kept my own date logic honest while building HolidayOps.
5 minThe Engineering Logs
06RAG Retrieval Strategies on a 50k-Document Dataset: BM25 vs Dense vs Hybrid
How BM25, dense embeddings and hybrid search (RRF) behave on a 50k-document RAG corpus: working code, honest trade-offs, and when each one actually wins.
11 minThe Engineering Logs
07The Discount That Knew You Were Hesitating: Rule-Based Personalisation in an Online Pharmacy
How Zovita+ turns browsing into personal discounts without a machine-learning model: one visitor key for guests and customers, interaction counters, six offer rules, one pricing function for the bag and the charge, offers locked and redeemed once at checkout, guest-to-account merging, A/B tests, and the edge cases that shaped it.
10 minThe Engineering Logs
08One Seat, Two Buyers: Race Conditions, IDOR and Keys in a Cinema Booking System
How BookMyMovie makes sure one cinema seat is never sold twice, a guessed booking number shows nothing, and a leaked or missing key can't quietly break tickets: row locks, lock order, a NULL-tolerant unique key, status compare-and-set, idempotency, IDOR scoping, HMAC tickets, captcha step-up, and the bugs that still got through.
11 minThe Engineering Logs
09The Last Mango Problem: Race Conditions in a Real Marketplace
What happens when fifty people try to buy the last item, use a single-use coupon or book a nearly full pickup window at the same instant, the MySQL snapshot detail that almost overbooked a stall, and the quieter races that hide in stock forms, restocks and payments.
10 minThe Engineering Logs