MockMate AI - Intelligent Interview Coach
Voice-first preparation platform for practicing technical interviews. Simulate realistic interview rounds with speech-to-text answers, receive immediate rubric-based ratings and critiques, and track performance improvements over time.
Executive Summary
The Challenge
Practicing for technical interviews alone makes it hard to assess your own responses objectively, and cloud transcription adds unnecessary cost.
The Solution
Browser-native Web Speech API for zero-cost transcription, Google Gemini 2.5 Flash with strict JSON schema for structured feedback, and MongoDB for session persistence.
Measurable Impact
Fast rubric evaluation, zero transcription cost through browser-native speech, and structured feedback with score, critique, and model answers.
Technologies
Key Decisions
Why Server Actions over API Routes?
Since we needed direct, low-latency database mutations from the client form, Server Actions eliminated the need to maintain boilerplate API routes.
Why Gemini 2.5 Flash?
Interview feedback requires near-instant responses. Gemini Flash offered the perfect balance of speed and high reasoning capabilities over heavier models.
Why native Speech Recognition?
Instead of dealing with heavy audio file uploads and server-side transcription, using the browser API handled it locally with zero cost and zero latency.
Retrospective
Hardest Part
Handling edge cases with browser compatibility for the native Speech Recognition API, especially across different mobile devices.
Biggest Insight
Achieving reliable AI outputs in production requires treating schemas as contracts. Enforcing strict JSON schema validation and atomic credit decrement before LLM calls eliminated hallucinations and edge-case double spending.
Do Differently
I would implement WebSockets for streaming the AI response word-by-word instead of waiting for the full JSON block to load.
Key Highlights
AI Question Generation
Generates 5 unique technical questions based on Job Role & Tech Stack.
Voice-to-Text Engine
Records user answers in real-time using browser-native Speech API.
Instant AI Feedback
Analyzes answers to provide 1-10 ratings and improvement tips.
Interview History
Dashboard to track performance trends and review past feedback.
Open to opportunities