What Is Topalupu?
Topalupu is an AI-powered interview preparation platform designed to simulate the exact experience of interviewing at the world's top technology companies. Unlike traditional coding practice sites that give you a problem and a "Submit" button, Topalupu puts you in a live interview simulation with an AI interviewer that asks follow-up questions, gives hints, challenges your approach, and evaluates your performance — just like a real human interviewer would.
The platform covers three interview pillars: coding interviews, system design sessions, and behavioral rounds — each customised for Google, Amazon, Meta, Apple, Microsoft, and NVIDIA.
The Problem Topalupu Solves
Traditional Prep Is Broken
The current interview prep ecosystem has a fundamental flaw: it teaches you to solve problems, not to interview well.
The gap between "can solve problems" and "performs well in interviews" is massive. Candidates who solve 500+ LeetCode problems still fail interviews because they never practiced the social, communicative, and improvisational skills that interviewers actually evaluate.
Mock Interviews Are Expensive and Hard to Schedule
Professional mock interviews cost $100–300 per session on platforms like Interviewing.io or Pramp. Finding experienced engineers willing to practice is difficult, scheduling is a hassle, and the feedback is inconsistent.
Topalupu solves both problems: you get an always-available AI interviewer that simulates a realistic interview for a fraction of the cost.
How Topalupu Works
Step 1: Choose Your Target Company and Role
When you sign in, you select the company you're preparing for — Google, Amazon, Meta, Apple, Microsoft, or NVIDIA — and the specific role. Each company has distinct interview patterns:
- Google: Heavy focus on algorithms, system design at scale, and the "Core Competencies" behavioral round
- Amazon: Leadership Principles drive every behavioral question; coding focuses on practical, service-oriented problems
- Meta: Speed-focused coding (2 problems per round), product sense for senior roles, billion-user scale system design
- Apple: Deep technical interviews with team-matching; secretive process with emphasis on craftsmanship
- Microsoft: Growth mindset culture; "As Appropriate" final round with hiring manager
- NVIDIA: Systems-level depth; GPU architecture, parallel computing, CUDA-specific questions
Step 2: Start an Interview Session
Each session simulates a real interview round:
#### Coding Interview
You enter a full-featured in-browser IDE with syntax highlighting. The AI interviewer presents a problem, and you work through it live:
- The AI asks you to clarify the problem
- You explain your approach — the AI responds with follow-up questions
- You write your solution in Python, JavaScript, Java, or C++
- Your code runs on real Judge0 infrastructure — actual execution, not simulated
- The AI evaluates your solution for correctness, efficiency, edge cases, and code quality
This isn't a chatbot. The AI adapts to your approach in real time. If you're stuck, it offers hints. If you choose a suboptimal approach, it challenges you to think about better alternatives. If you miss edge cases, it probes them.
#### System Design Session
You're given a design prompt like "Design YouTube's Video Upload Pipeline" or "Design a Distributed Rate Limiter." The session follows a structured flow:
- Requirements gathering — the AI plays the role of product manager
- High-level architecture — you propose components, the AI asks why
- Deep dive — database schema, caching strategy, failure modes
- Scale and trade-offs — the AI pushes you on bottlenecks and alternatives
- Evaluation — scored on completeness, scalability, trade-off awareness, and communication
#### Behavioral Round
For each company, the AI tailors questions to their specific culture and values:
- Google's "Core Competencies" (leadership, collaboration, impact)
- Amazon's Leadership Principles (Customer Obsession, Ownership, Bias for Action)
- Meta's "Move Fast" culture (speed, boldness, impact)
For objective-type questions, you select the best answer and get instant feedback. For open-ended questions, the AI evaluates your STAR (Situation, Task, Action, Result) response and scores it.
Step 3: Get Detailed Feedback
After each session, you receive a comprehensive report with scores on:
Each dimension is scored independently, so you know exactly what to improve.
The Technology Behind Topalupu
AI Interviewer: Google Gemini
The core of Topalupu's interview simulation is powered by Google Gemini, Google's most advanced AI model. Gemini provides:
- Context-aware follow-up questions based on your specific code and explanations
- Adaptive difficulty — the AI adjusts its probing based on your skill level
- Real-time evaluation — instant scoring with specific, actionable feedback
- Company-specific personas — the AI adapts its interview style to match each company's culture
Code Execution: Judge0
Your code doesn't run in a sandbox simulator. Topalupu uses Judge0, the same infrastructure used by competitive programming platforms, to execute your code against real test cases. You see:
- Actual runtime in milliseconds
- Memory consumption
- Test case pass/fail results
- Edge case coverage
Question Bank: Curated and Company-Specific
Every question on Topalupu is sourced from real interview reports and tagged to specific companies:
Problems are tagged with difficulty (Easy, Medium, Hard), company frequency, and the specific patterns they test.
Full-Stack Architecture
Topalupu is built on a modern, production-grade stack:
- Frontend: Next.js 15 with React 19, Tailwind CSS
- Backend: Next.js API routes with server actions
- Database: PostgreSQL via Supabase with Prisma ORM
- Authentication: NextAuth.js with Google OAuth
- Payments: Stripe for subscription management
- AI: Google Gemini API for interview simulation
- Code Execution: Judge0 for real-time code running
- Hosting: Vercel for edge-optimised deployment
Pricing Model
Topalupu uses a freemium model designed to let you experience the platform before committing:
The Free tier isn't a crippled trial — you get real interview simulations with full AI feedback. It's enough to experience the platform and decide if it's worth upgrading for unlimited access to premium companies.
Case Study: From LeetCode Grinding to Interview Confidence
The Problem
A typical Topalupu user — let's call her Priya — had spent 4 months grinding LeetCode. She'd solved 300+ problems. On paper, she was ready. But when she sat down for her Google phone screen, she:
- Panicked when the interviewer asked clarifying questions she hadn't prepared for
- Coded silently for 10 minutes before the interviewer interrupted to ask about her approach
- Finished with a working solution but couldn't explain the time complexity when asked
- Received a rejection email 3 days later
The Root Cause
Priya could solve the problem. What she couldn't do was interview. She'd never practiced:
- Thinking aloud while coding
- Responding to follow-up questions in real time
- Explaining trade-offs between different approaches
- Testing her code systematically while narrating
The Solution
After finding Topalupu, Priya ran 15 practice sessions over 3 weeks. Each session forced her to:
- Communicate her approach before writing code (the AI won't let you start coding without explaining)
- Handle interruptions — the AI asks follow-up questions mid-solution
- Explain complexity — the AI specifically probes time/space analysis
- Test systematically — the AI asks "what edge cases might break this?"
The Result
On her second Google attempt 6 weeks later, Priya passed the phone screen and received an onsite invitation. The interviewer's feedback specifically noted her "clear communication and structured approach."
The difference wasn't more LeetCode problems. It was practicing the interview format itself.
Who Is Topalupu For?
Perfect Fit
- Engineers preparing for FAANG interviews who want realistic practice
- Career switchers who need to learn the interview format, not just the algorithms
- International candidates who want to practice English-language technical communication
- Anyone who's failed a big tech interview and wants to understand why
Not a Replacement For
- Learning data structures from scratch — Topalupu assumes basic CS knowledge
- Getting your first referral — we help you pass the interview, not get one
- Compensation negotiation — though our blog covers this extensively
What Makes Topalupu Different
Start Practising
Topalupu is live and fully functional — not a demo, not a waitlist. Sign up, pick your dream company, and run your first mock interview in under 2 minutes.
The interview is the hardest part of getting hired at a top tech company. Make sure you've practiced it, not just the problems.