Nubank adopts AWS Graviton processing and optimizes costs by 14%

Created by AWS to provide the best price-performance ratio for workloads running on Amazon Elastic Compute Cloud (Amazon EC2), AWS Graviton processors began to be assessed by Nubank in 2021. Since then, the institution has been following the evolution of these processors, as well as AWS services compatibility for Amazon ElastiCache, Amazon RDS and OpenSearch, for example. According to Puente, this is when the first experiments with the processors began.

One of his team's premises, according to him, is to define the simplest and easiest ways to test hypotheses. In the case of AWS Graviton processors, testing began with some microservices and databases. “That’s how we started. Then we expanded the scope. In some cases, we were forced to revisit our infrastructure after testing—a process of experimentation and learning that allowed us to achieve full impact across different applications,” he says.

Nubank's systems engineer, Carlos Diogo, recalls that the first phase of testing included a benchmark to understand how the new processors would work. “They were processing twice the volume with the same latency,” he reveals.

The testing phase lasted about a year, after which the Nubank IT team decided to enable its entire structure for the new processors. Once the decision was made, a new scaled rollout was planned, which actually began in the second half of 2022. “Our first machines started migrating in October of that year in a process that is still ongoing,” he says, mentioning the data environment, which was migrated in three weeks, as an example.

Nubank's product operations lead, Daniel Capp, explains that the migration revealed some challenges, such as prioritizing the adoption of the new processors with the Nubank teams and rebuilding some plugins. He recalls that the Data Analytics team, for example, underwent internal training before the migration. “Today we ran the entire Analytics workload on AWS Graviton,” he says.

Diogo stresses that the migration process brought some very positive surprises, such as the absence of runtime problems. “We also had no problems with the service libraries or with the Amazon ElastiCache migration,” he says.

According to Puente, today the entire Nubank microservices environment is enabled to work with AWS Graviton. “In our storage layer, part of the workload already uses Graviton, but the Datomic database is still being validated. There are other very specific workloads,” he explains, remembering that there will always be one that connects in a specific way, or to a specific software. For these demands, Nubank and AWS are working on a case-by-case basis.

“We are taking it slowly with specific services. For example, our Pix feature is more real time and uses a very specific architecture. We have service level agreements (SLAs) with the Central Bank that cannot be broken. These nuances have to be worked on cautiously”, she reveals, remembering that caution is important to maintaining service stability. This is the phase in which the migration process is today: defining what Puente calls specific points and then migrating the latest services. In any case, today the institution has more than 90% of its services enabled for or running on AWS Graviton.

Despite it is still migrating, Nubank is already able to see results from using its services with AWS Graviton processors. Puente reveals that, so far, there has been a 14% optimization in cloud usage costs.

On another front, Nubank further reduced its carbon footprint. The institution, which has had negative emissions since 2020, reduced emissions by another 21% by using the new processors. In addition, the institution was able to develop a flexible architecture that allows it to use whichever processors are most efficient based on demand. “Our architecture today runs on both AWS Graviton and x86,” Puente reveals. The use of this multi-architecture model allows the institution to achieve benchmarks and run its workload on the one that is most efficient, taking into account cost and stability.

With these results, Nubank is already preparing for the use of third generation processors, which will bring improvements compared to the results obtained so far. “The changes we made allow us to use the AWS Graviton versions and that’s why we are looking forward to AWS Graviton 3, which should increase our efficiency,” he says, revealing that tests of the new version are already underway with promising results in the storage layer, for example.