HUY.
EDTECH × SRS2024Creator & Full-stack Developer

SynapQ

An intelligent, text-based interview preparation platform powered by Active Recall & Spaced Repetition (SM-2).

SynapQ is a focused, text-based interview preparation system built on proven cognitive science principles: Active Recall, Spaced Repetition (SM-2), and simulated pressure. Designed to help candidates retain deep technical & behavioral knowledge and express it clearly under time constraints without relying on bloated voice AI.

The Problem

Traditional interview preparation is passive and ineffective: candidates read answer banks without active recall, forget information quickly due to the Ebbinghaus forgetting curve, and experience severe anxiety under real interview time constraints.

The Solution

Built a full-stack platform combining a customized SM-2 Spaced Repetition algorithm that schedules reviews precisely before forgetting occurs, alongside time-pressured Mock Interview sessions with visual countdowns and key-point checklists for metacognitive self-evaluation.

Unified Next.js full-stack architecture leveraging App Router, Server Actions, and Route Handlers, connected to a relational PostgreSQL database via Prisma ORM for type-safe query execution and authenticated with NextAuth.js.

Execution Flow & Pipeline:
01SRS Scheduling Engine: User Rating (Again / Hard / Good) → Quality Score (q) → Ease Factor Update (EF) → Dynamic Interval Calculation → Next Review Date
02Mock Interview Pipeline: Configured Deck → Time-pressured Countdown (with visual warning states) → Notes Input → Reveal Checklist → Metacognitive Rating
03Session & Analytics Flow: User Action → Session Review Logging → Daily Stats Aggregation → Streak & Retention Dashboard Visualization

Customized SM-2 Spaced Repetition Engine

Dynamically calculates ease factors and optimal review intervals across learning, review, and relearning card states.

Real-Time Mock Interview Simulation

Simulates interview room pressure with interactive countdown timers, urgency color shifting, and post-session performance metrics.

Checklist Metacognition & Cue Keywords

Enables users to verify their recall against structured key points and unlock gentle keyword hints when stuck.

High-Efficiency Keyboard Shortcuts & Undo

Full keyboard navigation (Space, 1/2/3, H, Ctrl+Z) with a 5-second rating undo window for lightning-fast study sessions.

Analytics Dashboard & Streak Engine

Tracks daily study consistency, retention rate graphs, card maturity breakdown, and motivational milestone badges.

Practice Out Loud Mode

Dedicated verbal articulation mode prompting candidates to speak their answers aloud before verifying against model solutions.

CHALLENGE:Adapting SM-2 to a 3-Button Evaluation System

Approach: Mapped the standard 6-grade SM-2 quality scores into an intuitive 3-button scheme (Again=1, Hard=3, Good=5) with modified interval growth formulas for Hard ratings.

CHALLENGE:Type-Safe Relational Schema for High-Frequency Progress Tracking

Approach: Modeled UserCardProgress, StudySessions, and DailyStats with Prisma ORM on PostgreSQL, adding compound indices on [userId, nextReviewDate] to ensure instant query times during card queues.

CHALLENGE:Zero-Latency UI During Rapid Card Reviews

Approach: Implemented optimistic state updates and seamless keyboard event listeners with debounce protections to keep card flipping instant.

Deployment

Deployed and running live in production at https://143.198.212.224.sslip.io/ with managed PostgreSQL and automated workflows.

Result

Successfully launched to production at 143.198.212.224.sslip.io, serving active users for technical, behavioral, and system design interview preparation.

Technologies Used

Next.jsTypeScriptPostgreSQLPrisma ORMNextAuth.jsSM-2 AlgorithmVercel

Personal Contribution

  • Designed the entire product vision, cognitive learning principles, and user flows
  • Engineered the full-stack Next.js application with Prisma ORM and PostgreSQL
  • Implemented the mathematical SM-2 Spaced Repetition calculation engine
  • Crafted the minimalist, high-contrast dark theme and responsive UI with keyboard shortcuts