Rental management system with a public API


From one line of code to $1M in fundraising

BookingSync grew out of a single line of code into a community of 160 investors. In 2014, they raised the first round of investment of more than $1M in a fundraising blitz that lasted only 15 days.


realization: 2014-2018


Property management software

BookingSync is a vacation rental software offering centralized property management with distribution to platforms like Airbnb, Booking.com, and Trip Advisor. It centralizes all marketing efforts, reservations, payments, and so on, and continues with steps like email notifications, generating websites for clients, and providing invoicing.


Develop and extend the app functionality

Booking itself is made through a co-product and many modular apps using our public API. One of the biggest challenges was to build a central app. There’s the main operating system with apps plugged in on top of it. Some of them are made by the BookingSync team, and some by other developers and external vendors. BookingSync needed a robust system in terms of APIs, authorization, record control, etc.


Long-term backend development


Our work resulted in a growing community of developers building distributed applications with the new API.

Splitting the monolith

The new API allowed a successful migration from a monolithic system to a microservices architecture.

Reduced time

We reduced the time required to build new channels integration to about 30 days.

A two-way integration

We used the API to build two-way integrations with multiple channels, such as Booking.com, HomeAway, and Airbnb.

Payments refreshment

We introduced PCI DSS-compliant architecture for credit card payment processing.

Flexible team

Along the way, we increased our involvement by up to 7 developers during the peak.

All in one

We helped improve all areas of the application taking responsibility for the technical side.

Tech Stack

Web development & JSON:API



API integrations


active rentals

Sébastien Grosjean, CEO

Ragnarson took responsibility, making the project their own and doing everything possible to make it work.

The API we've released has around 200 partners currently. Some of them have told us that the system is one of the best they've seen in the industry. We've had fast integrations with partners like Airbnb, for which the process took 34 days. Some of our competitors still have problems after one year, so it was a huge difference. Airbnb has come to value our technical skills, which also speaks to the capabilities of Ragnarson.

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