Willi Guillerme Rittmann

Designed and built a Jetpack Compose dynamic, GraphQL-driven form system that renders fields, validation rules, input masks, and field interdependencies at runtime from a single UI state object, eliminating one-off forms across the module. Created the “payment-form at-change” flow from scratch, including a complete address flow (form, search, edit) as part of a loan and internationalization initiative. Worked on migrating the module from legacy architecture to MVI + Compose during a company-wide migration from multiple repositories into a single monorepo, contributing shared utilities and optimizations. Implemented internationalization abstraction layers enabling per-country injection across the app. Worked exclusively with GraphQL/Apollo (no REST), maintaining 85%+ test coverage and using Datadog for observability and Jenkins for CI/CD in an Agile/Scrum environment.

Sole Android developer for an EdTech startup in Indonesia, rebuilding a legacy teacher-booking/scheduling platform from scratch. Owned the end-to-end mobile architecture, modularization strategy, requirements gathering, and key UI/UX decisions while working in a fully English-speaking remote team. Learned JNI from scratch to integrate a C/C++ layer as one of the data sources behind the repository layer. Built a complex Jetpack Compose scheduling screen with an infinite-scroll calendar including zoom and navigation by date/month/year. Researched and integrated a non-Google map pinning API due to budget constraints, implementing custom map tiling and rendering. Identified and raised scope and process issues (uncontrolled scope creep and unjustified technical decisions) to project leadership.

Wrote automated integration tests for one of the world’s largest social media apps, including advertising-related features, maintaining ~80% test coverage. Adopted the Page Object pattern for the first time, improving test readability and maintainability (still in use). Collaborated in a mixed local/remote setup, syncing daily in English with US-based management.