SWOP

After very quietly launching, we had a couple of beers to celebrate, but we didn't really think of what would be next.

When deciding to grow our side-project into a real product, we thought that it might help that we're the only ones offering a GraphQL endpoint.

Much to our surprise someone thought the same and used a search engine to find a Currency Exchange Rate API that offers GraphQL. It looks like the swop.cx result caught their eye :)

Naturally a product needs a name, we came up with SWOP. We registered the .cx domain which from this point on will be known to be the abbreviation for "Currency Xchange" instead of Xmas Island.

We have thoroughly checked the quality of out data, have all monitoring and alerting setup, so we publicly launched.

So we set out to build a Currency Rates API that meets our requirements. Development began on the side in October 2019 with an initially limited feature set to our specific needs, but we decided at one point, that we should go further. Over the first half of 2020 our little side project evolved a lot, so we eventually decided to take the next step and turn it into a full-fledged SAAS product to be offered to all in need of a Currency Rates API.

As 2019 was coming to an end and a bigger client project was just finished, we had some spare time for a side project.

The foreign exchange rate API topic came back to mind and seemed like a good fit. The size of the project was perfect for our time budget and the technologies we wanted to try out.

We started with the following broad goals:

• A high quality API that could serve as a showcase for our work
• GraphQL API as well as REST endpoint
• Quality documentation and example code to ease integration
• Secure connections for every user
• Fast response times
• CI pipeline and testing strategy from the start

We were looking for an API that serves up-to-date currency rates in order to implement a currency-conversion feature for Kittysplit (a side business we are part of). We compared a few different APIs and integrated one of them. It worked well enough, but there were a couple things we didn’t like. First it was REST only, as was the entire competition. A secure connection was only provided for paid plans. Response times were often slow and some other annoyances.

Nevertheless we started integrating and using it, but kept in mind, that a currency rates / conversion API that meets all our demands would be a nice future side project for us.