In the world of Fintech, where seamless financial transactions are critical, every millisecond of delay could impact customer experience and business operations. Here in Capri Loans as a leading Non-Banking Financial Company (NBFC), places high value on speed, efficiency, and security in delivering financial services. Understanding the full journey of an API request helps us design and optimize our systems to ensure we meet these high standards. Let’s break down the API request process, highlighting why each step matters and how it helps our tech team fine-tune performance.
The Journey of an API Request: How Every Millisecond Counts
1. Domain Name Resolution
- DNS Lookup: When a client (e.g., our loan application system or customer-facing platform) makes an API request, the first step is resolving the domain name to an IP address via DNS (Domain Name System). This step is crucial as any delay in DNS resolution directly affects the user experience. For example, when a customer applies for a loan, the request first goes through a DNS server to retrieve the IP address of our API endpoint.
- Impact on Latency: Optimizing DNS settings and ensuring quick lookups can shave precious milliseconds off the request time.
2.AWS API Gateway
- Request Reception: Once the domain name is resolved, the API request is sent to the AWS API Gateway. The API Gateway is the entry point to our backend services, processing the request, enforcing security protocols (like authentication and rate limiting), and routing it to the appropriate backend system.
- Why This Matters: This is where our Fintech API handles things like user authentication, ensuring only valid, secure requests make it through. Every delay here affects the transaction speed, so optimizing request flows and security measures is critical to reducing response times.
3.Load Balancer
- Distributing the Load: After processing by the API Gateway, the request moves to the load balancer, which ensures traffic is evenly distributed across multiple servers. This helps prevent any single server from being overwhelmed by too many requests, ensuring smooth operation even during high-traffic periods, such as during loan disbursements or customer onboarding.
- Health Checks: The load balancer continuously monitors the health of the servers to ensure requests are only sent to operational instances, improving reliability.
- Importance: Ensuring quick routing and healthy server checks can significantly reduce processing delays, improving customer experience.
4. Application Server (e.g., Gunicorn)
- Request Handling: Once the request reaches the application server (for example, Gunicorn), it is passed through the WSGI interface to the backend web framework (like Flask or Django). Here, the core business logic is executed.
- Business Logic Execution: This is where the bulk of the action happens — from processing customer details to interacting with databases to execute transactions, generate loan statuses, or retrieve financial data.
- Why This Matters: Every millisecond counts, especially when processing financial transactions. Streamlining this process and optimizing database queries can lead to faster, more efficient responses.
5. Web Server (e.g., Nginx)
- Reverse Proxy & Response Handling: Nginx acts as a reverse proxy, managing incoming requests and forwarding them to the application server. It also handles static content and can cache responses. Once the application server processes the request, Nginx sends the response back to the client.
- Importance for Fintech: Nginx can also handle SSL/TLS termination, which is critical in securing financial data transmissions. Efficient caching and response management by Nginx can drastically reduce response times, especially for frequently accessed resources like customer data.
6. Returning the Response
- The Return Journey: After the application processes the request and generates a response (e.g., loan approval or account statement), it is sent back through the same chain: from the application server (Gunicorn) to the web server (Nginx), back to the load balancer, API Gateway, and finally to the client.
- End Result: The client receives the response, completing the transaction, whether it’s a loan disbursement, payment confirmation, or account inquiry.
How This Understanding Helps Us Optimize Performance
In Capri Loans, understanding the complete flow of an API request gives our tech team the insight to optimize every step of the journey. By identifying bottlenecks at each stage — from DNS lookup to load balancing, from business logic execution to response caching — we can reduce latency and improve the overall customer experience. This attention to detail helps us deliver faster, more reliable services, ensuring that customers can make transactions and access services without delays.
In Fintech, every millisecond matters. Knowing the intricate details of how our APIs operate helps us design better systems, reduce latency, and meet the high expectations of our customers.
Author – Rohit Roy
