Cultivating a loyal customer base by providing innovative solutions and an exceptional experience should be the goal of any company, regardless of industry. 

This is one of the main reasons why Capital One uses Python to power a large number of serverless applications, giving developers a better experience as they deliver business value to customers.

Python has a rich toolset with codified best practices that perform well in AWS Lambda. Capital One has been able to take modules, whether they were developed internally or from the Python community, and put them together to build what is necessary inside of a fully managed compute instance.  

“We have vibrant Python and serverless communities within Capital One which has helped us advance this work,” said Brian McNamara, Distinguished Engineer.

Why Python for Serverless

Python and serverless practices are closely aligned in the development lifecycle which allows for quick feedback loops and the ability to scale horizontally. Using Python for serverless also allows for:

  • Faster time to market: Developers use Python to quickly go from ideation to production code. Serverless applications developed with Python allow developers to have their code deployed on a resilient, performant, scalable, and secure platform.
  • Focus on business value: Lower total cost of ownership so developers can focus on features instead of maintaining servers and containers; addressing operating-level system concerns; and managing resilience, autoscaling and utilization.
  • Extremely fast scale: Serverless is event-driven which helps with fast scaling, so it’s important to think of API calls, data in a stream, or a new file to process as events. For example, with built-in retry logic from cloud services, a Python serverless function can process the non-critical path from durable cues so the customer experience is not impacted.
  • Reusable resources: The Python ecosystem provides great resources and the AWS Lambda Powertools Python package is based on a number of open source capabilities. AWS Serverless Application Model also allows for a local testing experience that generates event examples.
  • Flexible coding style: Python provides a flexible coding style allowing developers to blend functional programming, data classes and Object Oriented Programming to process the event.
 Observability Benefits

Additionally, Furman and McNamara emphasized that using Python to power serverless applications has provided Capital One with countless observability benefits so that developers know what is happening inside an application.

“Observability in serverless can be often perceived as more challenging, but it can also be more structured with libraries that codify logs, telemetry data and metric data. This makes it easy to codify best practices,” said Dan Furman, Distinguished Engineer.

Furman and McNamara also pointed out the importance of leveraging the vastness of both the serverless and Python ecosystems. Looking at the knowledge that has been acquired by other members of these communities allows for organizations to gain the benefit of their experiences. 

McNamara and Furman will be giving a presentation on using Python to power serverless applications at PyCon US 2023, taking place at the Salt Palace Convention Center in Salt Lake City Utah from April 19-27. For more information about PyCon US 2023, visit the website.