Marshall Shen
Verified Expert in Engineering
Full-stack Developer
Marshall is an accomplished technical leader with a strong background in building AI software and leading engineering teams. He has delivered innovative solutions for tech companies of all sizes in fintech and healthcare. With over three years of experience running startups, he has led engineering teams of over 20 people, including offshore teams in China. As a software architect at Venmo, he builds scalable payment systems, mentors engineers, and builds a resilient engineering organization.
Portfolio
Experience
Availability
Preferred Environment
MacOS
The most amazing...
...app I've built is Venmo, extending it with consumer financial products such as credit and debit card.
Work Experience
Senior Staff Software Engineer
Venmo
- Developed a credit card product that scaled to more than 500,000 active users, with over $1 billion annual transaction processing volume.
- Migrated a monolithic Python Django application into a microservices architecture, with a React web front-end, MySQL and DynamoDB as data storage, and Kafka as data streaming.
- Functioned with technical leadership, overseeing and mentoring over 40 software engineers within the organization.
AWS Architect
One Step Holdings LLC
- Consulted with clients to determine their business needs.
- Developed software designs using AWS to meet those needs.
- Created a Python/Docker codebase that lets clients quickly begin product development.
Senior Developer
Therapy App LLC
- Built expert HIPAA-compliant data pipelines for personal patient data.
- Served 40+ mental health clinics across the US, providing practical solutions tailored to each client's needs.
- Delivered requested patient information within tight timelines without sacrificing quality.
Staff Software Engineer
Braintree
- Built a payment processing solution for enterprise merchants like Uber and Airbnb and handled a daily processing volume of over $10 billion using Ruby on Rails, Postgres DB, and Kafka stream.
- Created banking integration with National Australian Bank to launch payment processing service across all Braintree merchants in Australia.
- Oversaw a financial audit process to ensure the financial ledger met compliance requirements.
Senior Software Engineer
PatientPoint
- Launched a new product that managed digital content across 10,000+ IoT devices. Used Ruby on Rails for the back end, Vue.js for the front end, and Postgres DB as data storage.
- Acted as a tech lead for a team of ten developers and prioritized development tasks with the product and leadership team.
- Designed RESTful APIs and relational database systems for healthcare content streaming from scratch.
Software Engineer
Groupon
- Launched an internal accounting service to help merchant payments and developed payment algorithms that processed more than 1 billion USD of payments.
- Developed and maintained the Ruby on Rails app with more than 100,000 merchants globally.
- Worked with the Groupon finance and accounting team to help process and reconcile payments.
Experience
Venmo Credit Card
https://venmo.com/about/creditcard/I was a tech lead for this project, leading the high-level architectural design and guiding 40+ software engineers.
HackerPen
I created this platform and launched it in April 2022. As of September 2022, the platform is running with 300+ active users.
Maestro
The technology used: React Native, AWS Lambda, with RESTful APIs.
The app achieved over 2,000 downloads during the first six months of launch on iOS and the Google app store.
BuildU
I worked as the CTO of the company, and I was in charge of building the application and managing the software development process.
Kana - Learn Japanese
Skills
Languages
Python 3, Java, Ruby, Bash, TypeScript, HTML, JavaScript, Python, CSS, Elixir, PHP, GraphQL, Scala, SQL
Frameworks
Django, Ruby on Rails (RoR), Spring, Spring Boot, Material UI, MUI CSS, Bootstrap, Flutter, React Native, Angular, Laravel
Libraries/APIs
Ruby on Rails API, React, REST APIs, Node.js, OpenAPI, Vue, QuickBooks API
Tools
Git, Jira, Slack, Terraform, Google Compute Engine (GCE), Amazon EKS, RabbitMQ, Cron
Paradigms
API Architecture, Test-driven Development (TDD), Unit Testing, Agile Project Management
Platforms
Docker, MacOS, Amazon Web Services (AWS), Linux, Google Cloud Platform (GCP), Kubernetes, Firebase, Heroku
Storage
MySQL, PostgreSQL, MongoDB, Google Cloud, Cloud Firestore, Databases, JSON, Company Databases
Industry Expertise
Project Management
Other
Software System Architecture Development, Technical Leadership, Software Development, Algorithms, APIs, Back-end, Back-end Development, Web Development, Integration Testing, Software Testing Automation Framework (STAF), User Interface (UI), Full-stack, ESLint, Enterprise, Enterprise Systems, Software Architecture, GitFlow, Architecture, Computer Science, Amazon RDS, Technical Program Management, Chrome Extensions, Team Leadership, Artificial Intelligence (AI), Computer Security, Statistical Analysis, Statistical Modeling, Interaction Design (IxD), Fintech, CTO, Technical Project Management, AWS Certified Developer, CSV
Education
Master's Degree in Computer Science
Columbia University - New York, NY, USA
Bachelor's Degree in Statistics
University of Iowa - Iowa City, IA, USA
Bachelor's Degree in Computer Science
University of Iowa - Iowa City, IA, USA
Certifications
Functional Programming Principles in Scala
Coursera
Deep Learning Specialization
Coursera
Interaction Design Specialization
Coursera
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