Merchant Reporting (current) :

Incremental enhancements to existing reporting products. Worked on the entire lifecycle of a new product launch (Custom Statements). Heavy refactoring of existing codebases. Building instrumentation, monitoring and alerting mechanisms.
Challenges: Inherited and ramped up on a vast system involving several components across various technical stacks (Javascript, Java, C++, NodeJS, Backbone). Handling critical production issues.

Resolution Center Experiences:
Built the UI and the front end application for resolving transaction related disputes.
Challenges: Learning and keeping up with the modern web technology stack (React, ES6, Webpack). Adopting an early version of an internal framework and working out the irregularities and nuances.

Merchant Onboarding Services:
Fixed the functional test automation suite of the mid-tier onboarding service. After the effort, the test suites were green giving us greater confidence on our releases.
Challenges: Large number of tests cases (~600 test case files) required creating scripts to parse and process test data files.

Built a performance monitoring interactive dashboard for a ~180 node Druid production cluster. The dashboard allowed developers to drill down to the root cause of the problems that were causing their Druid queries to run slower. Learnt about distributed systems, Druid, Server development with NodeJS, AngularJS, visualization libraries like D3 and NVD3.