Overview
A multi-exam preparation platform engineered for standardized and professional certifications including GED, Digital SAT, TOEFL iBT, GRE, CompTIA, and Real Estate. Built on the Next.js App Router, the platform pairs timed full-length practice simulations with an AI Study Assistant strictly grounded in verified curriculum notes through Retrieval-Augmented Generation (RAG).
My Role
Lead Front-End & Systems Engineer responsible for Next.js web architecture, timed test simulation engines, RAG tutor integration, and subscription workflows.
The Problem
Students preparing for high-stakes exams need realistic timed exam environments and fast access to past papers without clunky PDF downloads. Furthermore, general-purpose AI tutors frequently hallucinate unverified formulas and incorrect answers, undermining study trust.
The Solution
Engineered a performant Next.js web application featuring: - Timed exam simulation runner with question breakdown, autosave drafts, and topic diagnostics - Grounded AI Study Assistant using RAG strictly bounded to verified curriculum notes with source citations - In-browser document streaming for past papers eliminating heavy file downloads - Interactive study pacing and readiness timeline calculators - Integrated customer billing portal and subscription lifecycle handling via Stripe webhooks
Architectural reasoning
To prevent AI hallucinations, the study tutor operates through a closed-loop RAG pipeline. Prompts are matched against structured curriculum notes; any claim lacking verified source citations is stripped before streaming the answer to the student.
Technical Decisions
- Adopted Next.js App Router and Server Components to maximize Core Web Vitals and organic SEO across exam landing pages
- Implemented strictly scoped RAG retrieval to guarantee 100% citation-backed AI explanations
- Structured client exam state with persistent local storage fallbacks to prevent answer loss during network drops
Architecture
- Next.js App Router with Server Components for fast initial page load and SEO indexing
- Retrieval-Augmented Generation (RAG) pipeline bounded to verified course curriculum notes
- Deterministic timed exam state engine with client autosave across interruptions
- Secure document streaming architecture for in-browser past paper revision
- Stripe billing portal integration with automated subscription retries and grace periods
Engineering Highlights
- Engineered support across 7 standardized exam tracks including GED, SAT, TOEFL, GRE, CompTIA, and Real Estate.
- Built timed practice exams with real-time scoring simulation and passing benchmark comparisons.
- Integrated RAG AI Notebook providing step-by-step math and science problem solving with verifiable source tags.
- Implemented interactive study schedule calculator tailoring preparation pacing to weekly hours.
- Designed clean, responsive UI with Tailwind CSS and accessible navigation patterns.
Results & Impact
- Full-length timed practice exams and weakness diagnostics across 7 exam tracks.
- Grounded AI tutoring with verifiable curriculum source citations.
- In-browser past paper streaming with zero client file downloads.