Building from Zero Tomo’s Engineering Journey Photo by Chris Tradgett on Unsplash Audrey Troutt VP Engineering Tomo auditty audreytroutt 

Planting Seeds Where we began Photo by Jonathan Kemper on Unsplash 

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● Hire super senior team ● Build a distributed engineering org ● Use AWS ● Integrate lots of 3rd party APIs ● Implement lots of business logic and financial calculations ● Need workflows and state management ● Value security and reliability over speed or concurrency Overall, optimize for speed of development and flexibility Photo by Jonathan Kemper on Unsplash Starting Assumptions 

● Architecture: Microservices ● Languages/Frameworks: React/JS and Python/Flask ● Data storage: Aurora Postgres and S3 ● Containerization: EKS and Fargate ● Terraform: yes ● Monitoring: Datadog ● Source control and CI/CD: Github and Concourse Again, optimizing for speed of development and flexibility Photo by Jonathan Kemper on Unsplash First Decisions 

Continuous Delivery We are committed to continuous delivery and will make investments to make it safe to work that way. This enables our larger Tomo orientation around a bias for action and learning as fast as we can. 

Collective Ownership Teams own problems not services or apps. Every team member can make code changes where necessary. We are all responsible for quality, security, and DevOps. 

People over Process We trust in people to do the right thing and use process and structure as long as it helps us and doesn’t get in the way. 

● Architecture: Microservices ● Languages/Frameworks: React/JS and Python/Flask ● Data storage: Aurora Postgres and S3 ● Containerization: EKS and Fargate ● Terraform: yes ● Monitoring: Datadog ● Source control and CI/CD: Github and Concourse Again, optimizing for speed of development and flexibility Photo by Jonathan Kemper on Unsplash First Decisions 

Taking Root Building momentum leading up to launch Photo by Jen Theodore on Unsplash 

Use Debt, Responsibly There are times when it is appropriate to take out that credit card and spend. We use debt to buy something essential like a refrigerator, but not something unnecessary like a pinball machine. And pay it back. 

● Terraforming → Terragrunt and Atlantis ● Source Control and CI/CD → Gitlab and Gitlab Pipelines ● Environments → Actually have prod (and be able to create env from scratch) ● Container management → Rancher ● Moved us-east-1 to us-west-2 ● Added support for AWS SAM Add a SRE Team Photo by Jen Theodore on Unsplash 

We Launched! June 30, 2021 

If I could go back in time ● No cute names ● Set up monitoring and alerting sooner ● Build end to end experience first ● Use debt responsibly sooner ● Be opinionated about contractor projects Photo by Jen Theodore on Unsplash 

Pruning and Repotting Encouraging growth where needed Photo by Zoe Schaeffer on Unsplash 

Growth In the Right Areas Photo by Zoe Schaeffer on Unsplash ● Teams ● Planning ● Testing ● Tools ● Policies Still optimizing for speed of learning and flexibility 

Strategic Platform Investments We make time to craft and prioritize for the big changes that make Tomo’s rapid experimentation and growth possible. 

Eventual coherence It’s okay to try something new or make a simple first implementation because we come back and clean it up. 

Knowledge Sharing Information should be searchable and discoverable. We have a bias for transparency. We anticipate what future teammates will need to know to keep building and make sure that gets captured and shared appropriately. 

Growth In the Right Areas Photo by Zoe Schaeffer on Unsplash ● Teams ● Planning ● Testing ● Tools ● Policies ● Strategic platform investments ● Eventual coherence ● Knowledge sharing Optimizing for speed of learning and flexibility 

https://therealdeal.com/2022/03/24/mortgage-start up-tomo-expands-as-competition-pulls-back/ How is it going? 

Harvesting and the cycle continues Photo by Demian Tejeda-Benitez on Unsplash 

What is next? Photo by Demian Tejeda-Benitez on Unsplash Do it again at a new scale 

Photo by Demian Tejeda-Benitez on Unsplash Building from Zero Tomo’s Engineering Journey Audrey Troutt VP Engineering Tomo auditty audreytroutt Want to join us? hellotomo.com/careers