Multilevel Speaking App

Mobile Application Developer (Solo Developer) Multilevel Speaking App (CEFR Examination Platform) End-to-End Product Engineering: Architected, developed, and deployed the entire mobile application single-handedly from scratch to production, catering to national CEFR/Multilevel exam candidates. Core Exam Simulation Engine: Designed and built a strict, timed test simulation environment mirroring actual examination conditions (Part 1, 2, and 3), featuring automated topic transitions, preparation countdowns, and non-blocking speech recording. Audio Processing & Media Pipeline: Implemented robust native audio recording, compression, and local caching pipelines to ensure low-latency playback, minimal battery drain, and zero audio loss during mock tests. Backend & Cloud Architecture: Built the supporting backend infrastructure and RESTful APIs to handle question banks, dynamic topic updates, secure user authentication, and audio file cloud storage (AWS S3 / Firebase). AI & Evaluation Integration: Integrated Speech-to-Text and AI evaluation APIs to transcribe audio responses, detect grammatical errors, analyze vocabulary range, and provide automated scoring feedback to candidates. Offline-First & State Management: Engineered a robust local caching mechanism allowing candidates to practice offline, seamlessly synchronizing audio records and test analytics once network connectivity is restored.

BEST EDUCATION CENTER

Backend Developer BEST EDUCATION CENTER — CRM System & Mobile App Backend Core Backend Architecture: Designed and implemented a robust, modular RESTful API architecture from scratch to power both the web CRM and mobile client applications. Database Modeling & Optimization: Architected relational database schemas (tables, relations, indexes) managing complex business logic: student lifecycles, lead pipelines, dynamic course scheduling, staff management, and role-based permissions (RBAC). Financial & Attendance Engines: Developed the core financial accounting engine (tracking tuition fees, debits/credits, payment deadlines) and automated daily attendance tracking, reducing billing discrepancies and manual human errors. Integrations & Third-Party Services: Integrated local payment gateways (Click / Payme) and SMS service providers for automated transaction verification and trigger-based SMS alerts (payment receipts, debt reminders, schedule updates). Security & Authentication: Implemented secure JWT-based stateless authentication, password hashing, and granular access control to safeguard sensitive student and financial records. API Performance & Stability: Optimized heavy analytical queries and background tasks, ensuring fast API response times during peak usage hours.