Secure communication for modern education: a Signal-based chat module for “Mriia”.
- Kotlin, Java, Compose UI
- Swift, CoreData, EncryptedCoreData, SwiftProtobuf
- Protobuf, SQLCipher
- Signal-server
KEY RESULTS
CLIENT REQUEST
A communication app for the educational process between parents, teachers, and students was impossible without chats and convenient messaging features. The goal was to create a secure, scalable, and easy-to-integrate solution that fits seamlessly into the existing system architecture.
Given the large number of stakeholders and subcontractors, team flexibility, adaptability to changes, and proactivity played a crucial role throughout the development process.
MAIN CHALLENGES:
- Implement the Signal protocol without complicating the user interface;
- Account for a large number of stakeholders.
- Design a chat experience equally intuitive for children, teachers, and parents.
SOLUTION
The project was implemented step by step:
Stage 1 – MVP with Core Security Features
We began with UX/UI design and integration of the Signal protocol.
This allowed us to create a basic yet fully encrypted chat for the first users.
Stage 2 – Core Usability Enhancements
Added the ability to reply to messages, connect multiple devices to one account, and copy text — everything needed for seamless communication in chat.
Stage 3 – Extended Functionality
Introduced stickers, emojis, message pinning, file sharing, teacher moderation tools, and message editing and deletion.
The project involved product managers and designers from the client’s side, and from ours — Android and iOS developers, backend engineers, QA specialists, and a project manager. The process followed the SCRUM methodology with regular meetings, daily syncs, and close collaboration between all teams and subcontractors.
Project Manager’s Feedback
The project was a real challenge for our team – we worked with full awareness of the responsibility, knowing that this product would be used in almost every city in Ukraine. From the very beginning, it was clear that the solution had to be architecturally sound, as the expected load would be massive. We devoted a significant part of the time to building a reliable technical foundation. Since Signal is an open-source project without ready-made “out-of-the-box” solutions, we needed to deeply analyze the platform’s needs, forecast how the chat could evolve, and choose the right approaches from the start – without losing pace and while ensuring fast, high-quality delivery from the early stages. I believe the Devlight team became a powerful extension of the project, taking ownership of a highly specialized and complex module. Despite all technical challenges, the team delivered 125%. Very soon, Ukraine will have a modern, high-quality, and – most importantly – super-secure chat used by hundreds of thousands of people.
Andrii Zayats
Project Manager at Devlight
Final design
Simplicity and functionality in every element.
