How to scale an API Gateway

Increasing user traffic and API requests can mean your business is headed in the right direction. It can also mean you need to scale your API gateway. Let us take you through the benefits, challenges and practicalities of doing so.

Benefits of scaling an API gateway

Scaling an API gateway means it will be able to handle more concurrent incoming requests. The benefits include:

  • Enhanced performance
  • Reduced latency and response times
  • High availability – as you can distribute the load across multiple instances to protect against any one instance failing
  • Protection against performance bottlenecks as you increase throughput capacity 
  • Cost savings – with the gateway architecture dynamically adjusting resources in response to incoming traffic volumes, you can maintain optimal performance during busy periods while keeping your costs down when demand is lower

API gateway scaling challenges

Scaling your API gateway may present challenges in relation to:

  • Load balancing
  • Service discovery
  • Monitoring
  • Debugging
  • Managing shared states
  • Ensuring data consistency 

Thankfully, designing an effective gateway architecture can minimise these challenges.

Designing an effective architecture

Designing an effective architecture means implementing everything from synchronisation mechanisms for managing shared states to caching mechanisms and data storage solutions for ensuring data consistency across multiple instances. The latter is particularly important if you’re using a microservices API gateway, with the gateway interacting with multiple backend services.

Service discovery and client-side load balancing

Service discovery and load balancing are cornerstones of effective scaling. Distributing incoming traffic efficiently across multiple instances can be complex but is essential to smooth operation. As such, you must implement load-balancing mechanisms to share the workload evenly across each instance.

This increasing number of instances means that robust service discovery mechanisms are also essential. Service discovery supports the dynamic location of and connection to available instances.

Logging and monitoring

API gateway scaling can result in increased complexity, so it’s essential to log and monitor performance and resource utilisation. Doing so can ensure you are alerted swiftly to any potential issues so that you can troubleshoot them.


Automation tools can help you manage and streamline the scaling process, providing time and cost savings. They can help you provision and deploy infrastructure resources, configure and manage load balancers, implement monitoring and alerting mechanisms and more.


Considerations for scaling an API gateway

Different API gateways deliver different benefits and can significantly impact the cost of scaling. 

An on-premise API gateway delivers total control, flexibility and scalability. Installed on your own servers, it can be a great way to meet the requirements of stringent regulators. 

A cloud gateway solution delivers the ability to flex and scale, minus the infrastructure headaches. You can install it on your own servers, the public cloud or as a multi-cloud software-as-a-service (SaaS) solution.

Whichever you choose, remember that your API gateway needs to deliver robust security and authorisation mechanisms that can scale along with your business. Look for a gateway that lets you implement security at the platform level, so that every API in your portfolio enjoys the same security features. In addition to all major types of security, it can also be helpful to have the flexibility to create custom implementations.

Finally, consider the additional features that different gateways provide. An option such as Tyk’s open source API gateway, for example, delivers added benefits such as no vendor lock-in and superb community support.

Strategies for scaling an API gateway

The approach you take to API gateway scaling will depend on your use case and needs. These three common strategies can help: 

Database sharding involves horizontally partitioning data across multiple databases or shards, each containing a subset of the data. If you aim to reduce the load on a single database as you scale, this can be an effective way to deliver improved performance and increased throughput. As the data volume grows, you can add more shards, enabling scalable storage and higher availability (as each shard can have its failover mechanism or be replicated).

Caching strategies enable you to cache frequently accessed data, thereby reducing the load on backend systems and delivering performance improvements thanks to reduced response times and lower resource utilisation. Reducing the computational load on backend systems through caching can support effective scaling while delivering a superior user experience. 

Asynchronous processing involves queueing or scheduling tasks for later processing instead of processing everything synchronously and waiting for immediate completion. This operational task independence can handle more requests concurrently, thus supporting effective scaling while delivering greater resilience, fault tolerance and reduced response times.

How to optimise performance

Scaling an API gateway provides the chance to optimise performance through: 

  • Load testing and benchmarking to establish the maximum volume of concurrent requests that your API gateway can handle before performance is impacted. Measure request response time and latency to ensure that these improve as you distribute the load across multiple instances as you scale.
  • Optimising data structures such as hash tables, trees or caches means you can enhance performance in areas such as request routing, data lookup and response processing, delivering more efficient data retrieval and faster response times as you scale.
  • Optimising code quality ensures more efficient use of system resources such as memory, CPU and network bandwidth, enabling the API gateway to deliver optimised performance and handle higher loads.

How to troubleshoot issues with your API gateway

The increased complexity that API gateway scaling encompasses means that you need to be ready to troubleshoot. 

Use monitoring tools and services to ensure you’re fully abreast of what’s happening. Use observability tools to track and collect system health data and provide you with early alerts when something unexpected occurs, so you can troubleshoot any issues before your users are impacted.

As you scale the API gateway, use error handling and debugging to identify performance issues and isolate faulty components, resolving issues in real-time as they arise. Graceful error handling means the gateway can deliver meaningful and informative error responses for effective troubleshooting and debugging as you scale.

Best practices for scaling an API gateway

You can use various designs for your API gateway pattern, including using multiple patterns in combination with one another. Your use case, traffic volume, performance objectives and fault tolerance considerations will all play into which pattern(s) you use. Design patterns well-suited to API gateway scaling include:

  • A shared-nothing architecture gateway pattern, where each gateway instance operates independently for easy horizontal scaling
  • An event-driven architecture which supports asynchronous processing
  • A circuit breaker pattern, which improves resilience by preventing cascading failures

With your design pattern(s) chosen, bear the following best practices in mind. 

Automated deployment strategies

Using automated deployment strategies (examples include infrastructure-as-code tools and cloud-specific deployment services) means you can provision and configure API gateway instances as required as you scale.

Security considerations

Focus on robust authentication and authorisation mechanisms, employing secure communication protocols, implementing thorough input validation and data sanitisation techniques and applying rate limiting and throttling. 

Pay attention to secure configuration management as you scale and ensure that your monitoring and logging systems can detect and analyse any suspicious activities or anomalies to provide an early warning system for any potential security incidents.

Be sure to put security auditing and penetration testing arrangements in place to verify that everything is working as it should be.  

Integrating third-party services

As well as working beautifully with microservices behind the scenes, an API gateway can help with third-party service integration as you scale. Remember, however, that you must ensure those integrations are secure. That means verifying the third-party providers’ security measures, from data encryption to their authentication mechanisms.

Leveraging serverless computing

Leveraging serverless computing as you scale means you can focus on growth without worrying about infrastructure management – your cloud provider can worry about that instead. The elasticity of serverless platforms means you can focus on handling your increased traffic efficiently and optimally, delivering high availability and performance while minimising resource consumption.

Managing multiple environments

When managing multiple environments, you can scale efficiently using the guidance and best practices above. This means that you can optimise your development, staging and production environments so that scaling efficiency applies across the board.

How to manage API gateway costs as you scale

To manage your costs carefully, keep your usage patterns firmly in mind as you scale your API gateway. This will mean it is data driving your changes, ensuring your evolving infrastructure meets your usage needs without wasting resources. Other cost management tips include:

  • Using automation for dynamic scaling in response to traffic volumes and ensuring you don’t waste resources
  • Optimising your gateway to minimise unnecessary usage
  • Using caching and content delivery networks to reduce your data transfer costs
  • Implementing cost-effective storage (such as object storage services) 
  • Using your cloud provider’s tagging and resource grouping capabilities to track and categorise resources and identify areas for optimisation
  • Analysing usage trends over time to identify cost-saving changes and trends
  • Choosing a pricing plan that grows with your business

Ready for more? Then check out these other handy API gateway articles