Server for mobile application: backend API hosting

An optimal server for a mobile application, including its backend API hosting, typically consists of a VPS or a dedicated server with 4 GB of RAM or more, fast NVMe disks, and a stable communication channel, capable of efficiently processing API requests and managing user data, with an initial cost starting from $15-20 per month for small projects.

What is a backend for a mobile application and why is server choice important?

The backend is the invisible part of a mobile application responsible for data storage, business logic, user authentication, payment processing, sending push notifications, and much more. Without a reliable and high-performance mobile app backend server, your application will not be able to function fully, even if its frontend is perfectly designed. Choosing the right server is critically important as it directly affects the application's speed, stability, scalability, and the security of user data.

An incorrect choice can lead to slow loading, errors, data loss, and consequently, a negative user experience and audience churn. API server hosting must be able to withstand peak loads, ensure low latency, and be ready for user growth.

VPS or dedicated server: what to choose for your app backend hosting?

When choosing infrastructure for app backend hosting, developers and startups often face the question: VPS or dedicated server? Both options have their advantages and disadvantages, and the choice depends on the project's current needs, projected growth, and budget.

Virtual Private Server (VPS)

A VPS is a virtual machine running on a physical server alongside other VPS instances. You get dedicated resources (CPU, RAM, disk space), but the physical server is shared among several users. This is an excellent choice for startups and small projects.

• Advantages: lower cost, easy scalability (resources can often be quickly increased), configuration flexibility, full root access.
• Disadvantages: performance can be subject to the "noisy neighbor effect" (when other VPS instances on the same physical server consume many resources), limited capabilities for very high loads.

Dedicated Server

A dedicated server is a physical server that is entirely at your disposal. All its resources are available only to your application.

• Advantages: maximum performance and stability, full control over hardware, ideal for applications with high resource, security, and performance requirements.
• Disadvantages: significantly higher cost, requires more technical knowledge to manage (if a managed server is not chosen), scaling is more complex and takes longer (requires replacing or adding a new server).

For a more detailed comparison and choice, we recommend reading our article: VPS or dedicated server: what to choose for business.

How to calculate server requirements based on DAU and API requests?

Calculating application server requirements is an iterative process that begins with estimating the expected load. Key metrics:

• DAU (Daily Active Users): number of unique users per day.
• MAU (Monthly Active Users): number of unique users per month.
• Peak Concurrent Users (PCU): maximum number of users simultaneously using the application.
• Average Requests per User per Minute (RPU/min): average number of API requests from one user per minute.

Calculation example:

If you have 10,000 DAU, and at peak, 10% of users are simultaneously active (1000 PCU), each generating 5 requests per minute, then the total load on your API server hosting will be:

1000 PCU * 5 RPU/min = 5000 requests per minute (≈ 83 requests per second)

This is a basic estimate. Also consider the "heaviness" of requests (database read/write, image processing), the presence of background tasks, and potential growth.

• CPU: Responsible for processing business logic and requests. More cores and higher frequency are needed for intensive computations.
• RAM: Used for storing active data, cache, sessions. Insufficient RAM leads to swapping and slowdowns.
• Disk subsystem: NVMe SSD is essential for databases and fast file access.
• Network channel: 1 Gbps or 10 Gbps is important for fast data transfer and processing a large number of requests.

Push notifications, background tasks, and queues: how to ensure reliability?

Modern mobile applications actively use push notifications and background tasks to improve user experience and asynchronously process data. These components require special attention when planning a mobile app backend server.

• Push notifications: Apple Push Notification service (APNs) is used for iOS, and Firebase Cloud Messaging (FCM) for Android. Your backend must integrate with these services to send notifications. It's important that the server can quickly generate and send millions of notifications without delays.
• Background tasks and queues: Operations that do not require an immediate response to the user (e.g., sending emails, image processing, report generation) should be performed asynchronously. Message queue systems such as RabbitMQ, Apache Kafka, Redis Streams, or Celery (for Python) are used for this. They help offload the main API server hosting, increase fault tolerance, and ensure smoother processing of peak loads.

Example of using a queue with Redis:

import redis
import json

r = redis.Redis(host='localhost', port=6379, db=0)

def send_push_notification(user_id, message):
    # Logic for sending via APNs/FCM
    print(f"Sending push notification to user {user_id}: {message}")

def process_queue():
    while True:
        # Extract task from queue
        task = r.blpop('push_queue', timeout=1) # Blocking extraction
        if task:
            _, payload = task
            data = json.loads(payload)
            send_push_notification(data['user_id'], data['message'])

# Adding a task to the queue
# r.rpush('push_queue', json.dumps({'user_id': 123, 'message': 'Your order has been processed!'}))

CDN for media and static content: improving application performance

Most mobile applications contain media content: images, videos, audio. Loading these files directly from your application server can significantly increase its load and slow down the application for users far from the data center.

A Content Delivery Network (CDN) is a distributed network of servers that cache your content and deliver it to users from the node closest to them. Using a CDN for static files (images, CSS, JS) and media files has several advantages:

• Faster loading: Users receive content from the nearest server, which reduces latency.
• Reduced server load: The main app backend hosting is freed from serving static content, focusing on processing API requests.
• Increased fault tolerance: If one CDN node is unavailable, content will be delivered from another.
• Improved SEO: Fast content loading positively affects search engine rankings.

Valebyte.com offers servers with high-speed network channels (up to 10 Gbps), making them an excellent foundation for integration with a CDN and ensuring fast content delivery. For example, a Dedicated server with a 10 Gbps port is ideal for such tasks.

Scaling backend API hosting: from monolith to microservices

As your mobile application grows in popularity, its backend API hosting must be ready for scaling. There are two main approaches:

• Vertical scaling (Scale Up): Increasing resources (CPU, RAM, disk) on an existing server. This is the simplest method but has its limits.
• Horizontal scaling (Scale Out): Adding new servers and distributing the load among them. This is a more complex but also more flexible approach, allowing for virtually unlimited growth.

For horizontal scaling, the following are often used:

• Load Balancers: Distribute incoming requests among multiple instances of the mobile app backend server.
• Auto-scaling Groups: Automatically add or remove servers depending on the current load.
• Microservice architecture: Breaking down a monolithic backend into small, independent services, each of which can scale independently. This significantly complicates development but provides maximum flexibility and fault tolerance.
• Database scaling: Using replication (read replicas), sharding, or switching to NoSQL solutions for distributed data storage.

You can find additional information on scaling strategies in our article: How to scale a server with increasing load.

Security and fault tolerance of the application server

Security and fault tolerance are not options, but mandatory requirements for any application server, especially if it handles user data. Data breaches or downtime can cause irreparable damage to reputation and business.

• DDoS protection: Denial-of-service attacks can take your API server hosting offline. Choose a provider that offers built-in DDoS protection. Valebyte.com provides such protection on all its servers. Learn more: Dedicated server with DDoS protection: how to choose and how much it costs.
• Firewall: Configure a firewall to restrict access only to necessary ports and IP addresses.
• Backup: Regular automatic data backup is your last line of defense against data loss.
• Monitoring: Continuous monitoring of server performance (CPU, RAM, disk, network) and application status allows for prompt response to problems.
• High Availability: For mission-critical applications, server clusters can be configured with automatic failover to a standby server in case of primary server failure.

Recommendations for choosing hosting for your mobile app backend server

1. Start small: For an MVP or startup, choose a VPS with the ability to quickly scale vertically. This will optimize costs at the start.
2. Monitoring is key to success: Implement a comprehensive monitoring system from the outset to track performance and identify bottlenecks.
3. Geographic location: Choose a data center located closer to your application's primary audience to minimize latency.
4. Support: Ensure the provider offers 24/7 technical support that can promptly assist in case of problems.
5. Security: Priority number one. Look for a provider with DDoS protection, firewall configuration options, and regular security audits.
6. Disk type: Always choose NVMe SSD for maximum database performance and I/O operations.

Valebyte.com: ready solutions for backend API hosting

At Valebyte.com, we understand the unique needs that backend API hosting for mobile applications presents. We offer a wide range of solutions, from powerful VPS to high-performance dedicated servers, capable of meeting any requirements of your project.

• Flexible VPS: Ideal for startups and fast-growing projects, with instant resource scaling capabilities.
• Powerful dedicated servers: For applications with high load, critical performance, and security requirements. We offer servers based on the latest Intel Xeon and AMD EPYC processors, with NVMe SSDs and 10 Gbps ports.
• Global network of data centers: Choose the optimal location for your audience to ensure minimal latency.
• DDoS protection: Included by default for stable operation of your application server.
• 24/7 support: Our experts are ready to help with configuring and optimizing your infrastructure.

Whether you need a budget-friendly server for a mobile application for an MVP or powerful infrastructure for millions of users, Valebyte.com will provide a reliable and scalable solution.

Conclusion

Choosing the optimal server for a mobile application requires careful analysis of current and future project needs, balancing performance, scalability, and budget. Start with a VPS for MVP and small loads, and as the application grows, move to more powerful VPS or dedicated servers, actively using CDNs and queue systems for optimization. Valebyte.com offers reliable and flexible solutions for backend API hosting, capable of supporting your project at any stage of development.