The Problem We Were Actually Solving

When I first started looking at the issue, we were getting an average of 50,000 failed login attempts every month for users in these countries. Our error logs were filled with "502 Bad Gateway" responses, most of which were caused by ephemeral network losses in East Africa. The issue wasn't that our platform was unstable, but rather that our API was built for seamless global access, and it was the weak link.

What We Tried First (And Why It Failed)

Our initial solution involved implementing a failover mechanism for our API to switch to a backup server in case of network failures. Sounds simple enough. The problem was that our engineers got overly optimistic and started implementing various 'smarter' failover solutions, like dynamically routing users to the nearest available server. We ended up with a Frankenstein API that took an average of 2 seconds longer to respond to a request, and in some cases, it still failed. The error logs were still filled with "502 Bad Gateway" responses.

The Architecture Decision

We eventually decided to go with a different approach. We implemented a proxy server on the edge of our network, which cached responses to frequently requested data and provided real-time monitoring of network conditions. When a request was made to our API, the proxy server would check the underlying network conditions and then route the request to one of our servers based on the perceived latency and error rates. We chose to use NGINX as our proxy server because of its robust load balancing capabilities and its ease of integration with our existing stack.

What The Numbers Said After

The results were almost immediately apparent. Our error logs went from an average of 50,000 failed login attempts per month down to less than 100. Our platform was able to handle 90% more traffic without any performance degradation, thanks to the reduced latency and the better routing of requests to the nearest available server. Our customers in the least connected regions of the world were finally able to access our platform without interruption.

What I Would Do Differently

I would have pushed back on the idea of 'smarter' failover solutions earlier on. While they sound appealing at first, they inevitably lead to overengineering and make it harder to reason about your system's behavior. I would have also done more testing for our proxy server's caching mechanism to ensure it was handling edge cases correctly. In hindsight, a more straightforward approach would have saved us a number of headaches down the line.