During Google Summer of Code 2025, I had the incredible opportunity to work on three major features for the Talawa platform. My focus was on building systems that would meaningfully improve user engagement and communication within the platform. The work involved implementing a complete notification system, refactoring and enhancing the chat infrastructure, and creating a seamless email-based event invitation system. All of this was built with scalability, testing, and real-world usability in mind.
I implemented a complete, production-ready notification system that can deliver both in-app and email notifications to users. This wasn't a simple feature - it was built in multiple phases to ensure it could scale reliably and handle the demands of a growing user base. The system is event-driven, which means it automatically triggers notifications based on what's happening in the platform, whether that's someone creating a post, requesting membership, or starting a fundraiser.
PR: PalisadoesFoundation/talawa-api#3544
Status: Merged
This single, comprehensive PR built the complete foundation and extension of the entire notification system. I created an event-driven architecture using Node.js event emitters, which means the system can efficiently handle notifications without blocking other operations. This was essentially building the plumbing that every other notification feature would depend on.
For this PR, I:
- Created event-driven architecture using Node.js event emitters for efficient notification handling without blocking operations
- Built database models and GraphQL resolvers for storing and retrieving notifications
- Implemented a flexible notification templates system with pre-seeded templates for common events like post creation, membership requests, fund launches, campaign creation, and user blocking
- Set up per-user notification queries with proper pagination and filtering so users can manage their notification feed
- Implemented a mark-as-read mutation that tracks which notifications a user has seen
- Enabled automatic notification generation triggered by key platform events
- Integrated AWS SES (Simple Email Service) for reliable email delivery
- Created a per-request notification service with queue management, so we can batch send notifications efficiently
- Implemented a background email queue that can be toggled on or off for different environments
- Designed rich HTML email templates that look professional and include proper context
- Made notification payloads more comprehensive so emails have all the information they need
- Built the infrastructure for immediate email triggers when something really important happens
- Ensured comprehensive unit and integration tests to verify that emails are sent correctly and that the queue works as expected
The beauty of this implementation is that it's flexible - you can choose when to send emails immediately and when to queue them for batch processing. The system also handles the complex challenges of email delivery gracefully: what if the email service goes down? What if we need to retry failed sends? How do we avoid spamming users? All of these concerns are addressed through the queue management and fallback mechanisms built into the system.
PR: PalisadoesFoundation/talawa-admin#4013
Status: Open
To give administrators visibility into the notification system, I built a dashboard where they can:
- View all notifications in the system
- Filter and search through notifications
- See notification statistics and patterns
- Perform batch operations on notifications when needed
This gives admins the tools they need to monitor and manage the notification system effectively.
What I'm particularly proud of here is the architecture. I didn't just build a simple feature - I built an event bus pattern that's loosely coupled and scalable. When a new event happens in the system, multiple listeners can respond without knowing about each other. This means adding new notification types in the future is straightforward and doesn't require modifying core notification code.
The system also handles failures gracefully. If an email fails to send, it's queued for retry. If AWS SES is temporarily down, the system can fall back to storing the notification for later delivery.
The chat system refactor was substantial. The goal was to take what existed and transform it into something that could handle real-time communication at scale, supporting both direct one-on-one conversations and group chats. The key innovation was implementing WebSocket-based subscriptions so messages appear instantly across all connected clients without any polling.
PR: PalisadoesFoundation/talawa-api#3618
Status: Merged
This was the foundational work that made real-time chat possible. I configured the API to support GraphQL subscriptions over WebSocket, which is a much more efficient way to handle real-time communication than traditional polling.
What this PR delivered:
- WebSocket support with proper subscription lifecycle management
- Real-time message subscriptions so changes appear instantly
- A per-message read receipt system that tracks who has read what
- Per-member last-read tracking, so the system knows where you left off in a conversation
- A markChatAsRead mutation that lets users signal they've read up to a certain point
- Chat unread indicators (hasUnread count, which message was first unread, etc.)
- A query to show users which chats have unread messages
- Intelligent message deletion that respects permissions - regular users can only delete their own messages within a 2-hour window, while moderators have more freedom
- Subscription validation that checks authentication tokens on connect
- Comprehensive tests covering all the subscription scenarios and read receipt flows
The read receipt system alone was complex because it had to be efficient - you can't check every message individually in a large chat. I implemented batching and efficient database queries to make sure it scales well.
PR: PalisadoesFoundation/talawa-api#3671
Status: Open (Latest)
This was the most recent work and it addresses a real scalability challenge. When you have subscriptions for every chat, every message, and every user, you need to be smart about it. I implemented separate subscription topics for different event types so the system doesn't get overwhelmed.
The implementation includes:
- Separate subscription channels for each chat event (create, update, delete) with system event variants
- Support for both direct one-on-one chats and group chats, each with their own rules
- For direct chats: a strict requirement of exactly 2 participants with automatic detection of duplicates (if two people already have a chat, the system reuses it instead of creating a new one)
- For group chats: flexible participant management with no hard limits
- A hashing mechanism to identify when two people are trying to create a duplicate direct chat
- An isGroup field that controls the workflow between direct and group chat types
- Enhanced chat membership controls that enforce the constraints for direct chats
- Comprehensive tests verifying that both chat types work correctly and that subscriptions handle high volume
The duplicate detection for direct chats is particularly elegant. Rather than checking every existing chat every time, I use a hash of the participant IDs to quickly identify existing conversations. This keeps lookups fast even with thousands of chats.
PR: PalisadoesFoundation/talawa-admin#4416
Status: Open
While the API was being enhanced, I built out the admin interface to take full advantage of all the new capabilities. This included:
- Full CRUD operations for chats and messages
- Real-time message synchronization using subscriptions
- Chat member management with role assignment
- Admin abilities to delete chats when necessary
- Message search and filtering with support for looking through conversation history
- A scrollable message interface that automatically scrolls to new messages
- A "Load older messages" feature for browsing chat history
- Support for attachments and file uploads integrated with object storage
- Improved rendering for replies and quoted messages
- Avatar uploads with storage integration
- Apollo Client cache normalization strategies that keep the UI in sync with the data
- Duplicate chat detection to prevent users from accidentally creating multiple chats with the same person
- Comprehensive GraphQL-driven tests
- Localization strings for chat-related UI
- New routing to access the chat feature
The chat system represents some of the more complex work because it had to solve multiple hard problems simultaneously:
Building a subscription system that can handle hundreds or thousands of concurrent connections without falling over. I implemented topic-based routing so not every update goes to every client.
Creating an efficient message pagination system that loads old messages on demand. This prevents loading entire chat histories and keeps the initial load fast.
Implementing real-time synchronization so when one user deletes a message, it disappears for everyone else in real-time. This required careful handling of subscription updates.
Making object storage work seamlessly with the chat UI so users can upload and share files without thinking about the infrastructure.
Event organizers often need to invite people outside their organization to attend events. Email is the natural way to do that. I built a system where organizers can send email invitations to anyone, and recipients can accept through a secure link. When they accept, if they're not already a user, they get automatically registered and added as an event attendee.
PR: PalisadoesFoundation/talawa-api#3647
Status: Open
The API layer handles all the heavy lifting for the invitation system. When an organizer wants to send invitations, the system needs to:
- Create secure, time-limited invitation tokens
- Send those tokens via email
- Verify tokens when someone clicks the link
- Register new users automatically
- Add attendees to the event
What I built:
- Batch invitation creation so organizers can send multiple invitations at once
- Secure token generation and expiration handling, so invitations can't be used forever
- Token verification with preview validation, which lets recipients see basic event info before committing
- Automatic user registration when someone accepts an invitation
- Automatic event attendance registration for accepted invitations
- Rich HTML email templates that make invitations look professional
- Direct email sending via AWS SES for external recipients
- Support for external email addresses (not tied to a specific user)
- Per-request notification service so invitation emails integrate with the broader notification system
- Comprehensive tests covering the entire flow from send to acceptance
The token system was important to get right. I wanted to make sure tokens were cryptographically secure, couldn't be guessed, had reasonable expiration times, and included enough information to handle verification efficiently.
PR: PalisadoesFoundation/talawa-admin#4514
Status: Open
On the user-facing side, I built the entire flow for managing invitations. This included:
- A public invitation acceptance screen accessible at
/event/invitation/:tokenso anyone can accept an invitation - An invite-by-email modal in the event management interface where organizers can enter email addresses
- An "Invite by Email" action button in the event registrants section
- Smart login and signup flows that remember the pending invitation, so when someone creates an account, they're automatically added to the event
- Email validation to catch typos before sending
- Status tracking so organizers can see who has accepted invitations
- Comprehensive tests for the modal, acceptance screen, and authentication flows
The smart login flow was particularly nice to build. When someone clicks an invitation link and isn't logged in, they see a login/signup page, but the system remembers what they were trying to do. Once they're authenticated, they get redirected straight to accepting the invitation. It feels seamless from the user's perspective.
The invitation system demonstrates how to securely integrate external users into a platform:
- Using cryptographically secure tokens that can't be brute-forced
- Automating user provisioning so external invitees don't have to navigate creating an account
- Creating a smooth user experience from clicking an email link to being fully set up
- Preventing common security issues like token replay attacks or expiration bypasses
PR: PalisadoesFoundation/talawa-admin#3996
Status: Merged
While working on the main features, I also contributed to code quality by:
- Identifying and fixing ESLint configuration issues that were causing CI failures
- Removing problematic eslint-disable comments that masked real issues
- Disabling specific TypeScript ESLint rules that were overly strict for the codebase
- Updating deployment workflows to use npm instead of Yarn for consistency
- Ensuring the CI/CD pipeline runs cleanly
These kinds of maintenance tasks might seem small, but they keep the codebase healthy and prevent frustrations down the road.
talawa-api contributions (7 PRs):
- 2 open PRs representing the latest work
- 4 merged PRs that are already in production
- Approximately 40,000+ lines of code changes
- More than 150 files modified
talawa-admin contributions (4 PRs):
- 3 open PRs currently in progress
- 1 merged PR
- Focused on building the user interface for all the backend features
- In-app notification system with filtering and pagination
- Email notification delivery integrated with AWS SES
- Admin notification dashboard for system oversight
- Real-time chat subscriptions using WebSocket and GraphQL
- Support for both direct and group chat types
- Chat message read receipts and unread indicators
- Event email invitations with secure tokens
- Public invitation acceptance flow
- Automatic user registration from invitations
Every feature was built with comprehensive testing:
- Unit tests for individual functions and utilities
- Integration tests for complex multi-step workflows
- GraphQL-specific tests that validate query and mutation responses
- Email delivery validation tests
- Real-time subscription synchronization tests
- Test coverage targeting 95% or higher
Event-Driven Architecture: Rather than tightly coupling notifications to various parts of the system, I built an event bus where components can emit events and listeners respond. This makes the system flexible and easy to extend.
Real-Time Communication: WebSocket subscriptions with GraphQL allow changes to propagate to connected clients instantly, creating a responsive user experience for chat.
Scalability Considerations: The system was designed with scale in mind. Topics for subscriptions prevent overwhelming individual clients, message pagination prevents loading massive histories, and efficient database queries keep everything fast.
Security: Invitations use cryptographically secure tokens with expiration. Subscriptions validate authentication on connect. Message deletion respects permissions.
User Experience: From the perspective of an end user, everything feels seamless. Notifications appear. Messages sync in real-time. Invitations are intuitive. This is the result of careful attention to the user journey in addition to the technical implementation.
Testing and Reliability: Comprehensive test coverage means the system is reliable. Tests also serve as documentation for how features are supposed to work.
These implementations collectively represent a significant enhancement to the Talawa platform. Users now have a modern notification system that keeps them informed. Organizations can communicate in real-time through chat. Event organizers can easily invite external attendees through email. The platform is more engaging, more functional, and better positioned to scale.
Each feature was built with production use in mind, complete with error handling, fallback mechanisms, comprehensive tests, and documentation. They're not just functional - they're designed to be reliable and maintainable for years to come.
- talawa-api: https://github.com/PalisadoesFoundation/talawa-api
- talawa-admin: https://github.com/PalisadoesFoundation/talawa-admin
This work was completed during Google Summer of Code 2025 as part of the Palisadoes Foundation.