Scaling our 'What is my City Name' IP address lookup tool

Hey everyone, just looking for some practical advice here. We recently launched a super simple web tool called 'What is my City Name' – it literally just takes a user's IP address and tells them their city. Honestly, we built it as a quick side project, not expecting much, but it's really taken off and is getting a surprisingly good amount of traffic. It's awesome to see it being used, but our basic VPS setup is starting to groan under the load, especially when we get spikes in concurrent users. The IP address lookup functionality itself seems pretty resource-intensive, and our server costs are creeping up faster than we anticipated. We're trying to keep things lean, but performance is obviously key for a tool like this.

So, we're really scratching our heads trying to figure out the most efficient and cost-effective ways to scale. For high-traffic, low-latency IP address lookup tools, what hosting architectures or caching strategies have you found most effective? Are there specific IP geolocation APIs or databases that handle large volumes well without breaking the bank? Any recommendations on how to reduce server costs while maintaining snappy performance would be a lifesaver. Help a brother out please, any insights would be hugely appreciated!