YBG: nursing exam prep, test generation from minutes to seconds
Project Overview
YBG prepares US nursing students for their exams, from the HESI A2 entrance exam through NCLEX certification, with eighteen question types including image-based drag and drop. I worked on it at NUS Technology for 39 months, acting as lead developer alongside the team's official lead.
The Challenge
A legacy Rails codebase where the feature students use most, building a practice test, took 70 to 120 seconds. Traffic is spiky in the worst way: quiet for hours, then a whole class opens the same page at once and every slow query hits the database together. Deploys were slow enough that shipping a fix carried its own risk.
The Solution
I rebuilt test generation and the caching and database reads behind it, working on the paths that actually carried load rather than the ones that looked slow. I built out CI/CD pipelines so that deploying stopped being an event.
Outcomes
- •Cut test generation from 70–120 seconds to 3–7 seconds
- •Cut database read load by about 65%, with a cache hit rate near 90%
- •Doubled database query performance through query and schema work
- •Cut deployment time by 40% by building out CI/CD pipelines
- •Mentored developers, ran code reviews, and set the standards the team works to
- •As a team: page loads from about 4 seconds to under 1, and timeouts from 11% of requests to under 0.5%
Project Details
Client
YBG, through NUS Technology
Year
01/2023 – 03/2026
Category
Education
Technologies Used
Interested in working together?
Fixed-price audits, framework upgrades and Next.js modernization for Rails and Node applications.
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