What is Serverless Computing & Why use Serverless?

Serverless computing has changed the way developers build and deploy applications. The cloud provider takes care of the underlying servers, so developers can focus on writing code. The result is often faster development and less operational work.

In this article, we explain what serverless computing is, how it works, where edge functions fit in, and when serverless is (and isn't) the right choice for your application.

What is Serverless Computing?

1. Definition:

• Serverless computing is a cloud execution model where the cloud provider automatically allocates and manages servers. Servers still exist, but developers don't provision, patch or scale them. They write and deploy code, and the platform runs it when needed.

2. Key Characteristics:

• Event-Driven: Serverless functions run in response to events, such as HTTP requests, database changes, file uploads, queue messages or schedules.
• Auto-Scaling: The platform automatically runs more copies of a function as requests increase, and scales down (often to zero) when traffic stops.
• Pay-As-You-Go: Billing is based on actual usage, such as the number of executions and how long they run, rather than servers running all day.

How Does Serverless Computing Work?

1. Function as a Service (FaaS):

• The core concept of serverless is Function as a Service (FaaS). Developers deploy small functions that each perform a specific task. Functions run in response to events and are stateless: they don't keep data between runs, so anything that must persist goes into a database or storage service.

2. Cloud Provider Management:

• Cloud providers handle provisioning, scaling and maintenance. Popular FaaS platforms include AWS Lambda, Azure Functions and Google's Cloud Run functions. Google renamed Cloud Functions to Cloud Run functions in August 2024, bringing it under its Cloud Run platform, so older tutorials may still use the previous name.
• Developers upload their code, choose a runtime, and set up the triggers that run each function.

3. Integration with Other Services:

• Serverless functions connect to other managed cloud services, such as databases, file storage, authentication and messaging queues, to create complete applications.

4. Cold Starts:

• When a function hasn't run for a while, the platform may need to start a fresh instance before handling the request. This "cold start" adds a short delay. Choosing lightweight runtimes, keeping dependencies small, or paying for pre-warmed instances reduces the impact.

Edge Functions: Serverless Closer to Users

Edge functions are a newer form of serverless. Instead of running in one cloud region, the code runs on a provider's network of locations around the world, close to each visitor.

• Lower latency: Because the code runs near the user, responses can start faster. This helps when your audience is spread across Pakistan and abroad. Learn more in our guide to latency.
• Typical uses: Redirects, authentication checks, A/B testing, personalizing content by country or language, and modifying responses from a CDN.
• Trade-offs: Edge runtimes are usually more limited than regular functions, with restrictions on execution time, memory and supported libraries. Heavy processing or direct database connections often still belong in a regional function.

Many CDN and hosting platforms offer edge functions, and modern web frameworks such as Next.js can deploy parts of an application to the edge.

Benefits of Serverless Computing

1. Reduced Operational Complexity:

• Server management is handled by the cloud provider, so your team spends less time on patching, capacity planning and maintenance.

2. Cost Efficiency:

• You pay for actual usage, which often saves money for applications with variable or low traffic. For steady, high-volume workloads, compare costs carefully: always-on servers or containers can work out cheaper.

3. Automatic Scaling:

• The platform scales functions with demand, so applications can handle traffic spikes, such as a sale campaign or a viral post, without manual intervention.

4. Faster Time-to-Market:

• Simpler deployment and less infrastructure work help teams release features and new products more quickly.

5. Improved Resource Utilization:

• Computing power is allocated based on real-time demand, so you are not paying for idle servers.

Limitations to Consider

• Execution limits: Functions have maximum run times and memory limits, so long-running jobs may need a different service.
• Vendor lock-in: Triggers, configuration and connected services differ between providers, which can make moving platforms harder.
• Debugging and monitoring: Distributed functions are harder to trace than a single application. Plan for logging and monitoring from the start.
• Unpredictable bills: A bug or abusive traffic can trigger huge numbers of executions. Set budget alerts and rate limits.

Use Cases for Serverless Computing

1. Microservices Architecture:

• Serverless functions suit microservices, where each function handles one task or service, making the application modular and easy to scale.

2. Real-Time Data Processing:

• Serverless works well for processing streams of data, such as logs, IoT readings and file uploads (for example resizing images when they are uploaded), thanks to its event-driven design.

3. APIs and Backend Services:

• Functions can power APIs and backends that handle HTTP requests, read and write databases, and connect to other services.

4. Automation and Scheduled Tasks:

• Scheduled functions automate routine tasks, such as backups, report generation and data clean-up.

5. Webhooks, Chatbots and AI Automation:

• Serverless functions are a natural fit for receiving webhooks, for example from a payment gateway or a WhatsApp Business messaging integration, and for running automation workflows that call AI services only when a message or event arrives.

Conclusion

Serverless computing lets developers focus on code instead of servers. With automatic scaling, pay-as-you-go pricing and simpler deployment, it suits APIs, automation, event processing and applications with variable traffic.

It is not right for every workload. Cold starts, execution limits and vendor lock-in need planning. Used where it fits, and combined with edge functions for latency-sensitive tasks, serverless is a practical part of modern application development.

Experience the Future of Application Development with Serverless Computing!

Softhat builds web applications, APIs and automation for businesses across Pakistan, choosing serverless, edge or traditional hosting based on what each project needs. Explore our web development services, or book a free strategy call to plan your next project.