Hacker's Handbook


HappiHacking's Just in Time Development

An Agile Success Story with Klarna's Installment Plans

Posted: 2023-05-24

In the dynamic sphere of FinTech, rapid adaptation and swift delivery are true game-changers. My name is Happi, and during the nascent stages of Klarna, I served as the Head of Engineering. With a lean yet proficient team of five, we managed to manifest the vision of Klarna's flexible installment plans through rapid prototyping - setting a new precedent in agile development.

Klarna, a renowned name in global payments and shopping services, had a mission: to equip customers with the liberty to choose flexible payment installments. Translating this visionary objective into an operative reality required far more than a great idea. It demanded exceptional expertise, agile efficiency, and a profound comprehension of local rules and legislation.

Our project was about speed, yes, but it was also about careful compliance and precision. Harnessing our unique agile development approach, "the Happy Path", we were tasked with creating a system that met Klarna's specific requirements, complied with local regulations, and was delivered within an impressively short time. We started by thoroughly analyzing the proposed solution, then concentrated our efforts on delivering value swiftly and effectively.

In August, the project embarked, aiming to be ready for the Christmas shopping rush. We adopted incremental releases as a strategic tool to ensure continuous progress and timely delivery - an approach that epitomizes the potency of agile methodologies. This enabled us to gather regular feedback, make necessary adjustments, and adapt to ensure the final product perfectly suited Klarna's needs.

By October, just two months after the project kick-off, the first iteration of the installment plan system was launched. This was more than a major milestone; it was a demonstration of our formidable development skills and dedication to delivering within the deadline. This early release enabled webshops to begin offering installment plans as a payment method, even though invoicing end customers, receiving payments, or calculating interest were not yet functional. However, by fully understanding the service, we knew these components wouldn't be required until one month after the first customer purchase - leaving ample time for further development.

Post initial release, we relentlessly refined and enhanced the system, adding features just in time. Our efforts ranged from introducing invoicing and handling payments to calculating interest, all the while optimizing the system for performance, security, and usability.

By February, a short six months since project initiation, the system was not only live but also a dominant player in the Swedish market. This remarkable growth, both rapid and robust, underscores the effectiveness of our implementation strategy and the intrinsic value of the installment plan solution.

Our journey with Klarna's installment plan system is more than an agile success story. It's a testament to the power of understanding client needs, delivering rapid yet reliable solutions, and maintaining meticulous regulatory compliance in the FinTech industry. It's a reflection of HappiHacking's philosophy: to create high-quality, efficient solutions that make a genuine impact.

Through our unique blend of speed, precision, and agility, HappiHacking is constantly pushing the boundaries of what's possible in software development.

- Happi


Happi Hacking AB
Munkbrogatan 2, 5 tr
111 27 Stockholm