- Resolved deliverability issues between internal microservices and NetSuite by building new proxying rate-limiting Ruby on Rails microservice. Utilized Kafka, Sidekiq, and PostgreSQL to ensure exactly-once and in-order delivery. Actively monitored Kafka messages to ensure that all messages were processed.- Architected and refactored pending payments to be more reliable and introspectable. Collaborated with other engineers to log financial transactions using a graph data structure, persisted in PostgreSQL, in a Rails app. Drastically reduced errors by enforcing data consistency in database models prior to processing.- Implemented custom cursor-based pagination in GraphQL using hand-written SQL queries in Rails codebase, allowing scalable fetching from graph data structure. Wrote documentation and copious RSpec tests to ensure maintainability and extensibility.- Designed a system for managing automatic discounts using Rails, NetSuite, and an external promotions API. Built the system in one week, before the deadline and in half the allotted time. Set up Slack alerts to ensure customers received the discounts they deserved and iterated on approach to catch fewer false alarms.- Noticed invalid NetSuite and Rails staging data was hindering validation and deployment speed; cleaned up staging data to better allow QA to perform regression testing. Worked with QA to ensure their work would not be hindered during and after cleanup.

- Created an API performance monitor using Postman to ensure that changes in one microservice would not affect the performance of others. Researched Postman documentation to understand best practices.

- Built E2E tests using a variety of white-box, gray-box, and black-box testing frameworks including Appium, Selenium, and Detox. Wrote test cases in Java and occasional GUI tooling. Focused on durability to prevent false alarms.- Collaborated with the application engineers in agile development process to determine required test coverage.