Oscar Olivella developed a feature flag system for the wireapp/wire-ios repository, enabling controlled experimentation with chat UI bubble displays. He implemented an end-to-end toggle pathway that integrated Swift-based UI, configuration, and network layers, allowing seamless switching between simplified and alternative chat bubble modes. Oscar collaborated with QA and feature flag framework teams to ensure safe rollout and rollback procedures, and he established instrumentation hooks to measure user engagement for future A/B testing. His work demonstrated depth in feature flagging, mobile development, and iOS UI engineering, providing a robust foundation for iterative UI improvements and data-driven product decisions.