Developer Acceleration | SaaS

This App (this.so) Launches in Months with AWS Cloud Development Kit + Serverless Architecture

this.so needed infrastructure that would allow them to be agile, all while creating a solid scalable architecture to build on for years as they grow.


This App (this.so) Launches in Months with AWS Cloud Development Kit + Serverless Architecture

Imagine: you and your friends want to organize a catch-up coffee or take a fun weekend trip together, and you're trying to decide when and where. You probably juggle calendars over email or text, plan accommodations, meals, and schedule in a to-do list app or document, and split all the trip costs later with a calculator and Venmo. Using multiple applications gets the work done, but it's far from elegant.

Founded in late 2020, this.so aims to be the central place where friends and family can gather to coordinate calendars, chat about upcoming plans, and send money for everything from weeknight dinners to trips out of town. Their unified application will feature not just chat and video calling, but an intelligent event creation tool that syncs with your calendar, a decentralized digital payment network that connects to your bank account, and a tailored discovery feed of events, flights, and accommodations.

With only a five-person engineering team, this.so built and shipped their full-featured production beta to Apple TestFlight and the Google Play Store only one year after development began. Their chat functionality already includes groups, audio transcription, and video calling—feats that took other chat applications, such as WhatsApp, multiple years to complete. And the best part is: this.so is already built to scale.

"Everyone we talk to is blown away by what we've been able to do in such a short amount of time," says CTO Jeff Steinmetz.

In addition to having a talented founding group of engineers, Steinmetz credits the development speed and agility to a serverless architecture, early adoption of AWS Cloud Development Kit (CDK), and their team support partnership with Trek10.

"Our job was to build a product that our users would love,” said Steinmetz, “and that's where our focus needed to be. We just needed our servers to run—Trek10 understood that and made sure we got the best AWS had to offer."

Building Infrastructure as Code with AWS Cloud Development Kit

As a young startup, this.so needed infrastructure that would allow them to move fast and change direction on the fly, all while creating a solid architecture that will be scalable and easy to build on for years as they grow. To tick all those boxes, they and Trek10 got to work designing a serverless, event-driven architecture with AWS ECS Fargate, AWS Lambda, and DynamoDB.

The infrastructure is automated, meaning the team can focus their engineering efforts on building instead of maintenance. "We didn't want to think about Ops. Instead, we wanted to treat AWS like a utility, keep the lights on, so to speak, while we worked on code and features,” said Steinmetz.

To support the required levels of automation while lowering the barrier to entry for maintaining Cloudformation scripts, this.so’s infrastructure consists of AWS CDK projects, which are quickly gaining traction as a new way to write infrastructure as code in a familiar programming language without needing in-depth knowledge of Cloudformation.

"We wanted to give this.so a good foundation of CDK applications and projects that would allow them to move fast on things that are supposed to move fast and be stable on the things that are supposed to be stable," said Tim Van de Walle, Senior Lead Architect at Trek10.

AWS CDK automates the Cloudformation scripts using this.so’s preferred language, Typescript, and GitLab CI/CD pipelines control their deployments. The CDK projects are linked such that, when server code is updated, a new container image is built and stored, kicking off a new GitLab deployment pipeline using CDK.

Taking the plunge into AWS CDK was what jump-started this.so’s AWS management, said Steinmetz. Any time they had questions about best practices, organization, or setup, they could leverage the deep knowledge from Trek10's team. Partnering with Trek10 not only accelerated development but gave the whole team a higher level of confidence in AWS and the cloud.

"Trek10 taught us to fish,” said Steinmetz. “At this point, our whole team can work with CDK, and they're already adding new things to it, said Steinmetz."

Building a Scalable, Extensible Application

Project decisions always come with trade-offs; especially in greenfield projects, earlier architecture decisions sometimes need to be reimagined as the project evolves. As the team pushed forward on new features, Trek10 was there to offer an outside view on architecture, helping them make small changes that made sure their architecture set them up for future success.

For instance, when this.so first began work on their app, they had mobile app-driven events that needed to be resilient. As the app took shape, some of those events required logins to synchronize with their DynamoDB database. Trek10’s Van de Walle advised and helped develop the approach to manage those Cognito events using triggers. This pushed business logic into Lambda serverless functions, which kept their Fargate Apollo services as lightweight as possible, in service of this.so’s long-term growth strategy.

"When investors ask me if I'm ready to scale to millions of users, I can say yes,” said Steinmetz. “this.so has been well-architected, it's secure, everything is automated and scripted."

this.so Looks to the Future

As the team works toward their official launch to the App Store and begins to grow their internal team, they appreciate more and more how well-documented their code is. It's been incredibly easy to onboard new engineers so everyone can hit the ground running.

Steinmetz said that in their last team meeting, it hit him how meaningful it is that they've been able to build so much with a small and agile team.

"We've got investors, a healthy runway, and so many people telling us how much they love what we've built—our entire team is incredibly proud," he said.