— Developed an Android video-conferencing app withmessenger features using Java and Kotlin. Implemented newfeatures, fixed bugs and critical application issues such ascrashes and memory leaks. Conducted a comprehensiverefactoring of legacy code. — Developed an Android video-conferencing SDK using Javaand Kotlin. Set up a maven repository and implementedsupport for maven publication.— Greatly improved code maintability by standardizing apparchitecture and eliminating old workarounds.— Implemented a new in-app crash-report system fromscratch, drastically improving the speed of crash detection.— Significantly reduced app battery consumption byidentifying and fixing root issues related to app backgroundwork.— Contributed to the integration with C++ cross-platformlibrary using JNI.— Integrated different push services and organized theminto separate app builds.— Proposed and implemented new design feautures thatwere positively received by users.— Maintenaned Google Play console.— Mentored junior developers.