In early 2020, Zoom experienced an unprecedented surge in user growth, expanding from 10 million daily users to over 300 million in just a few months1. This remarkable scaling feat, achieved with minimal service disruptions, raises questions about the technology powering Zoom’s platform. The company’s ability to handle such rapid growth is attributed to its robust technical architecture and infrastructure design, which not only enables scalability but also delivers highly reliable video and voice conferencing services.

The Secret Behind Zoom’s Rapid Scaling

Zoom’s infrastructure was designed with scalability in mind from the outset. Prior to the pandemic, their network of 19 interconnected data centers operated at half capacity, providing ample room for initial user surges1. To manage the exponential growth, Zoom employs a flexible approach:

• Hybrid Infrastructure: Zoom utilizes both AWS and Oracle servers for non-meeting functions like call scheduling and participant management.
• On-demand Resource Allocation: While video calls typically run on Zoom’s data centers, they can be offloaded to AWS or Oracle servers during peak times.
• Elastic Scaling: This flexibility allows Zoom to expand or contract its AWS resources as needed, ensuring smooth meeting experiences.

Zoom’s Global Server Infrastructure

Zoom’s server architecture is designed to optimize user experience:

• 19 Interconnected Data Centers: These are strategically located worldwide to reduce latency in video calls.
• Geolocation Technology: Zoom employs geolocation to route users through the nearest data center, minimizing communication delays.

The Core of Zoom’s Success: Video Architecture

Zoom’s video architecture is built on four key pillars:

1. Distributed Architecture: Global data center distribution reduces latency and enhances video quality.
2. Multimedia Routing: Zoom’s multimedia router (MMR) efficiently manages multiple video streams of varying qualities.
3. Multi-bitrate Encoding: This technology allows a single stream to adapt to different resolutions, improving reliability and quality.
4. Application-level QoS: Zoom’s proprietary Quality of Service solution optimizes the experience for each specific device.

Zoom’s Technology Stack

Front-End Technologies

Zoom has developed native apps for various platforms:

• Android: Java
• iOS: Swift
• Web app: JavaScript/HTML/CSS
• Mac Desktop app: Swift/Objective-C
• PC Desktop app: C/C#/Java

Network Protocols

Zoom employs multiple network protocols:

• UDP (primary)
• TCP (fallback)
• SSL (secondary fallback)
• P2P (for two-participant calls)

Zoom’s High-Level Architecture

Zoom’s architecture comprises several key components:

1. Zoom Client: The user-facing application available on various platforms.
2. Zoom Data Center: Houses Meeting Zones, each consisting of an MMR and a Zone Controller.
3. Web Infrastructure: Hosts the zoom.us website and internal APIs.
4. HTTP Tunnel: Provides a fallback connection point in case of network issues.

Building a Video Conferencing App Like Zoom

While creating a Zoom-like platform requires significant resources, developing a video chat app can be more straightforward. Key considerations include:

• Choosing supported platforms
• Selecting back-end technologies
• Hiring skilled engineers

Developers can leverage existing technologies and SDKs to expedite the process of building video conferencing applications.

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