# Rafael Tanizawa > Full Stack Engineer - Specializing in Fraud Prevention & Risk Systems Location: San Mateo, California, United States Profile: https://flows.cv/rafaeltanizawa Seasoned Software Engineer with experience in developing highly available and scalable systems. Proven track record in both big tech companies and startup environments, excelling in roles that require strategic vision, technical expertise, and leadership. At Intuit, I played a pivotal role in migrating QuickBooks Payroll to AWS, significantly improving system performance and reliability. As a co-founder at Feedcast, I led technical direction and development efforts that drove measurable business growth and user engagement. Most recently, at Salsa, I designed and implemented a fraud prevention system from the ground up—detecting and blocking malicious activity in payroll workflows. The system successfully prevented multiple fraud attempts post-launch, improving platform integrity and protecting company funds. My expertise spans full-stack development, cloud infrastructure, fraud and risk systems, and mentoring engineering teams. Proficient in Java, Kotlin, React, GraphQL, AWS, Docker, and more. ## Work Experience ### Software Engineer, Founding team @ Salsa Jan 2022 – Present | United States As a founding member, I was instrumental in launching the company’s MVP, which enabled early customer traction and market validation. Drawing on my experience in fast-paced environments, I helped shape a culture of rapid iteration and innovation to keep the company competitive in a dynamic startup landscape. I led the end-to-end design and implementation of a fraud prevention system within our payroll product. This initiative involved architecting new processes to detect and block suspicious activity, integrating risk signals, and working closely with cross-functional stakeholders. The system successfully identified and prevented multiple fraud attempts shortly after launch, significantly increasing platform integrity and customer trust and preventing significant money loss for the company. ### Co-Founder @ Feedcast Jan 2019 – Jan 2022 | San Francisco Bay Area Feedcast was a platform enabling creators to sell audio courses in podcast format. As a technical co-founder, I led the overall technical direction and strategy of the company to ensure alignment with business objectives and market needs. The platform development included key features such as: - Payment Integration: Designed and implemented a seamless plug-and-play interface for Stripe account integration. - Mobile App: Developed an intuitive mobile app for iOS and Android to enhance the user experience for consuming audio courses. - Creator Dashboard: Created a comprehensive dashboard for uploading and managing courses and tracking sales. - Hosted Checkout: Engineered a high-converting, auto-generated checkout page optimized for selling online courses for each course in the platform. Achievements: - Launched a MVP that increased the customer sales by 25% by optimizing the checkout process and reducing cart abandonment. - As a result of our successful launch we raised a pre-seed round with Precursor Ventures, driving business growth. Technologies used: React Native (iOS and Android), React (Web), NodeJS (Backend), GraphQL, DynamoDB, AWS Lambda ### Senior Software Engineer @ Intuit Jan 2017 – Jan 2019 | Mountain View, CA Worked on the migration of QuickBooks Payroll to AWS, enhancing scalability, performance, and reducing operational costs. This role included the following responsibilities: - Datacenter Migration: Design and develop a lightweight service that routes traffic between AWS and legacy data center that can handle thousands of concurrent users in a reliable way; - API Development: Develop new GraphQL APIs to be compliant with our security standards and deprecating legacy APIs; - Performance Testing: Created and executed performance tests simulating thousands of concurrent users to evaluate and optimize infrastructure. - Knowledge Sharing: Presented tech talks to hundreds of engineers, explaining project impacts and overall architecture for the AWS migration. - Mentorship: Coached junior engineers, fostering career growth and adherence to best coding practices. Technologies used: Java, Spring Reactive, Spring Cloud Gateway, GraphQL, Docker, Kubernetes, Gatling (Performance Testing), AWS (EC2, S3, Route53, VPC, KMS, CloudFront, etc) ### Senior Software Engineer @ Intuit Jan 2015 – Jan 2017 | São Paulo Area, Brazil As one of the first Engineers hired in the Brazil office, I led the technical efforts for the successful launch of QuickBooks Online in Brazil. Responsibilities: - Architecture Design: Designed and built RESTful services in a SaaS environment to support new features for the Brazilian market. - CI/CD Implementation: Developed an automated deployment process and established a continuous integration environment using DevOps practices. - Monitoring and Troubleshooting: Implemented monitoring solutions and resolved service issues to ensure smooth operations. - Mentorship: Coached junior engineers, promoting career development and best coding practices. Achievements: - Successfully launched QuickBooks Online in Brazil, meeting all local requirements and gaining significant market traction. As a result, I was awarded with an offer to relocate to the headquarters in Mountain View, CA Technologies used: Java, Spring Framework, Oracle SQL Database, AWS. ### Senior Software Engineer @ UOL PagSeguro Jan 2012 – Jan 2015 | São Paulo, Brazil ### Software Engineer @ Neolog Consultoria E Sistemas Jan 2011 – Jan 2012 | São Paulo, Brazil ## Education ### Bachelor's degree in Computer Science USP - Universidade de São Paulo ## Contact & Social - LinkedIn: https://linkedin.com/in/rafael-tanizawa --- Source: https://flows.cv/rafaeltanizawa JSON Resume: https://flows.cv/rafaeltanizawa/resume.json Last updated: 2026-04-01