DevPal

Your AI-powered development companion — A mobile application that connects developers with tech events, daily code challenges, and intelligent code reviews.

Inspiration

The developer community often feels fragmented. Finding relevant tech events, staying motivated to practice coding, and getting constructive feedback can be overwhelming. DevPal was born as a digital companion that gathers all of that into a single gamified experience.

We wanted to solve three key problems:

Event Discovery: Hackathons, conferences, and workshops are scattered across many platforms
Consistent Practice: Maintaining a coding habit without structure is difficult
Accessible Feedback: Good code reviews aren't always within everyone's reach

What it does

DevPal is a mobile app that acts as your personal development companion:

Tech Event Discovery

Explore hackathons, conferences, and workshops on an interactive map
Filter by category and location
Save events and receive reminders

Daily Code Challenges

A new challenge every day generated by AI

AI Code Review

Paste your code and receive a clear and actionable analysis
Bug detection, performance improvements, and best practices
Suggestions tailored to your level

Gamification

Earn XP for completing challenges and attending events
Level up and unlock badges
Compete on the global leaderboard
Maintain streaks of consecutive days

How we built it

Frontend (Mobile App)

React Native + Expo (iOS, Android, and Web)
Expo Router for file-based navigation
NativeWind / TailwindCSS for consistent styling
React Native Maps + Leaflet for maps
Expo Secure Store for credentials
React Native Reanimated for fluid animations

Backend (API)

FastAPI as the main framework
PostgreSQL + SQLAlchemy for persistence
Google Gemini 2.5 Flash for:
- Daily challenges
- Code reviews
- Tech events
- Dev ecosystem news
APScheduler for scheduled tasks
RestrictedPython to execute code securely

Architecture

┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │ Mobile App │────▶│ FastAPI │────▶│ PostgreSQL │ │ (Expo/RN) │ │ Backend │ │ Database │ └─────────────────┘ └────────┬────────┘ └─────────────────┘ │ ▼ ┌─────────────────┐ │ Google Gemini │ │ 2.5 Flash AI │ └─────────────────┘

Challenges we ran into

Secure Code Execution

Running user code was critical. We used RestrictedPython to sandbox execution and prevent dangerous access.

Consistent Prompts

Getting Gemini to generate correctly formatted challenges required a lot of iteration and JSON validation.

Cross-platform Maps

React Native Maps doesn't work well on web, so we used Leaflet on web and RN Maps on mobile.

Costs and Rate Limiting

We implemented caching and rate limiting with SlowAPI to balance UX and costs.

Performance

Optimizing animations and images for low-end devices was an iterative process.

Accomplishments

Complete gamification system
Mobile code editor with real-time execution
Deep integration with Gemini
Scalable architecture
Polished UI/UX with glassmorphism and haptic feedback
Complete and secure authentication
Personalized onboarding

What we learned

Technical

Designing effective prompts for LLMs
Security when executing untrusted code
Gamification system design

Product

Immediate feedback is key
Gamification increases motivation
Personalization improves retention

Team

Constant frontend ↔ backend communication
Rapid iteration with real testing

What's next

Short term (v1.1)

Real-time multiplayer
More languages (Rust, Go, TypeScript)
Push notifications

Medium term

Integrated community
Personalized learning paths
GitHub integration
Mentorships

Long term

DevPal Pro
Options for companies or organizers to connect with institutions looking to rent out or offer venues for conferences, hackathons, etc.
Personalized news
Public API
Global expansion