During my tenure at IntelExpress, I led the full backend development of InexPay.ge, the company’s website, starting from the legacy system and completely rewriting it using ASP.NET Core 6.0. The project involved building a high-performance, scalable, and secure platform that supports financial transactions across 70+ countries. Key Responsibilities: Legacy System Support & Transition: * Provided critical support for the outdated WCF-based system, fixing security vulnerabilities and migrating plaintext password storage to BCrypt hashing. * Implemented 2FA for secure financial transactions, ensuring only the latest active SMS codes were valid. * Configured a new test environment, including server setup, DNS configuration, firewall rules, IIS setup, and database access permissions. Full API Rewrite: * Led the complete rebuild of the InexPay API using ASP.NET Core 6.0, following Clean Architecture principles for high performance, security, and scalability. * Integrated Microsoft.Identity & Keycloak for secure authentication and role-based access control. * Implemented advanced security measures including multi-factor authentication (2FA) and biometric authentication (fingerprint recognition). Fraud Prevention & Security: * Developed an advanced IP verification system, including real-time IP risk scoring, proxy/VPN detection, and dynamic IP blocking. * Created custom encryption mechanisms and ensured secure data exchange between the frontend and backend. * Introduced behavioral analysis, CAPTCHA, and bot detection mechanisms (Google reCAPTCHA) to prevent fraud and unauthorized access. * Conducted in-depth security analysis of incoming traffic and developed custom AWS WAF rules to mitigate DDoS attacks. Performance Optimization & Scalability: * Implemented API rate limiting with AspNetCoreRateLimit and optimized queries with Redis caching to improve response times. * Used BenchmarkDotNet to profile and optimize API performance, ensuring a smooth user experience. Microservices Architecture: * Transitioned InexPay towards a microservices-based architecture, developing independent services like: * Admin Panel: Role-based access to manage customer details, transactions, and verification processes. * AML Compliance System: Integration with state-level compliance APIs to ensure each transaction passed required checks. * Blacklist API: Real-time fraud detection service integrating with government databases. * Customer Verification API: AI-powered document verification system for identity checks using live camera interactions. * Exchange Rate Synchronization: Automated currency rate updates from state sources, with custom rules for exchange adjustments. * Payment System Integrations: Integrated with local banks and payment platforms to provide users with transaction receipts. Infrastructure & Security Enhancements: * Migrated the system to .NET 8.0, optimizing performance and updating outdated dependencies. * Integrated AWS WAF & CloudFront for DDoS mitigation, enhancing system security with Bot Control and IP whitelisting. Mobile App Support: * Adapted the API to support mobile-specific tokens and authentication flows for Flutter-based mobile apps. * Used DeviceDetector.NET to identify and differentiate between mobile and web traffic, ensuring tailored API responses. Collaborative Work: * Worked closely with cross-functional teams to ensure clear communication, timely delivery, and alignment with business objectives. * Led the transition to Agile practices, integrating JIRA, Confluence, GitLab, and enforcing GitFlow for better team collaboration. Outcome: * Successfully rebuilt InexPay from scratch, replacing an insecure legacy system with a modern, secure, and scalable solution. * Implemented robust fraud detection mechanisms, enhanced system security, and optimized transaction handling. * Improved user experience by optimizing API performance and ensuring seamless mobile integration.

As a .NET Instructor, I taught three distinct groups of students, each with varying levels of experience, focusing on C# programming and ASP.NET Core. I held two weekly 3-hour sessions for each group, totaling 18 hours of instruction per week. Teaching Schedule: * Monday, Wednesday, Friday: 3-hour sessions split between different groups. * Saturday: Back-to-back sessions for all three groups. Teaching Approach: * I combined theoretical lessons with live coding demonstrations and Q&A discussions. * Each group worked on collaborative projects where every student contributed ideas. * I assigned individual coding exercises and group projects, balancing structured learning with real-world problem-solving. * Regular assessments included quizzes, hands-on coding challenges, and project reviews. Results & Achievements: * Many students won C# programming competitions and hackathons, validating the quality of training. * Provided personalized feedback to track progress and guide students in improving coding practices. * After one academic year, I decided to step down from the role due to the challenge of maintaining teaching standards while working full-time and continuing personal development. Key Topics Covered: C#, ASP.NET Core, Clean Architecture, Web APIs, Entity Framework Core, Authentication & Authorization, SOLID Principles, Design Patterns, and CI/CD Basics.

Key Responsibilities: Agile Environment & Team Collaboration: * Worked in a three-person Agile team consisting of myself (BackEnd Developer), a Business Analyst, and a Project Manager. * Led and developed RESTful APIs without a dedicated FrontEnd team. * Managed collaboration in a fast-paced environment to meet project goals and deadlines. Project 1: API Development with Clean Architecture & PostgreSQL: * Designed and implemented an ASP.NET Core 6.0 Web API, adhering to Clean Architecture principles for scalability, maintainability, and performance. * Dockerized the application for consistent deployment across environments. * Integrated Keycloak for secure authentication and role-based access control, enhancing security. * Developed background jobs using Hangfire, including an admin dashboard with authorization features. Business Logic & Database Development: * Created advanced PostgreSQL functions to handle critical business logic, ensuring efficient data processing. * Stored the results in appropriate models and sent structured JSON objects to an external API using RestClient. * Managed sensitive data securely with User Secrets to avoid storing configurations in appsettings.json. Logging, Monitoring & Security: * Integrated Elasticsearch with Serilog for structured logging and real-time monitoring. * Developed Health Checks and implemented Integration Tests to ensure the API’s reliability and smooth functioning. * Configured secure authentication for third-party API data exchange, safeguarding sensitive information. Performance Optimization: * Used BenchmarkDotNet to analyze performance, identify bottlenecks, and make improvements to optimize execution time. * Focused on enhancing speed and efficiency without compromising security or best practices, meeting all business and performance requirements. Project 2: MSSQL-Based API with Advanced Stored Procedures: * Developed another standalone API project with MSSQL, using stored procedures to handle data-intensive calculations. * Utilized the Strategy Design Pattern to provide flexibility and avoid violating the Open-Closed Principle, improving code maintainability and scalability. * Reduced API-side logic by leveraging database stored procedures, improving performance and efficiency. Project 3: Support & Maintenance for DevExpress & Web API Projects: * Provided ongoing support for existing DevExpress and Web API projects, addressing bugs and optimizing performance. * Troubleshot and resolved issues to ensure the continued success of legacy systems. Project 4: RabbitMQ-Based Customer Sentiment & Sales Analytics System: * Designed and developed the entire architecture and business logic of the project, built on ASP.NET Core 6.0 Web API with RabbitMQ for event-driven communication. * Integrated SMS and email notifications to inform clients and internal teams about important system events. * Developed a system that tracked customer interactions and sales performance, generating automated actions like discounts for dissatisfied customers and escalating complaints to sales teams. Key Technologies Used: * Core Technologies: ASP.NET Core 6.0, MSSQL, PostgreSQL, RabbitMQ, Hangfire, Docker, Keycloak, Elasticsearch (Serilog), BenchmarkDotNet. * Development Tools: Entity Framework Core, Stored Procedures, Integration Testing, Health Checks, User Secrets, Design Patterns (Strategy, Clean Architecture), Event-Driven Architecture, RestClient, DevExpress. Outcome: * Successfully delivered several complex API projects, improving performance, scalability, and security. * Contributed to the development of advanced features like customer sentiment tracking, sales analytics, and dynamic actions based on customer interactions. * Ensured successful API implementations and system monitoring, meeting business requirements while maintaining high-quality standards.

Key Responsibilities: Agile Environment & Team Collaboration: * Worked as part of a cross-functional Agile team, which initially included a BackEnd Developer (myself), FrontEnd Developer, Project Manager, Business Analyst, and Tester (who left shortly after joining). * After six months, became the sole BackEnd Developer, taking over responsibility for all active projects and ensuring smooth maintenance, feature development, and architectural improvements. * Led knowledge transfer sessions and recorded video guides for existing projects following the departure of the Senior and Lead Developers. Project 1: Core Microservices Platform for TBC Pay Terminals: * Designed and maintained a microservices-based platform to handle transactions across TBC Pay’s self-service kiosks, both outdoor and in-store. * Developed multiple API Gateways for request routing, authentication, and load balancing, ensuring stability during high traffic. * Applied Flyweight and other design patterns to optimize system performance and resource usage. * Integrated with various banking and payment providers to support a wide range of financial operations. * Built an admin panel to monitor service health, detect financial leaks, and track expenses. Project 2: Real-Time Monitoring System for Payment Terminals * Developed a real-time monitoring dashboard to display the status and geolocation of all active kiosks in Georgia. * Integrated Google Maps API for live tracking and visualization of kiosk statuses. * Implemented automated alerts for administrators and security teams, triggered by device malfunctions, theft, or vandalism. * Automated the security response: tampered terminals were flagged, and security teams were automatically dispatched. Project 3: HR Management Platform with Admin Panel: * Created a full-scale HR platform to manage employee data, payroll, leave requests, certifications, positions, and access rights. * Implemented Role-Based Access Control (RBAC), restricting data visibility based on employee roles. * Automated payroll reporting, sending salary and employment data to government institutions. * Developed a request approval workflow for employees to request time off, which could then be approved, rejected, or modified by managers. * Built an admin panel for managing platform settings, assigning super admins, and adjusting permissions. Project 4: RabbitMQ-Based System Monitoring: * Developed a centralized monitoring system for tracking all running services, processes, and overall health of TBC Pay’s infrastructure. * Implemented event-driven communication via RabbitMQ to ensure reliable message exchange between microservices. * Built an admin panel to visualize system status, queue health, and real-time process execution, empowering administrators to troubleshoot and optimize system performance. Project 5: GateWay System for Payment Transactions: * Built a high-performance API Gateway serving as the intermediary between payment terminals and banking services. * Applied CQRS, Mediator, Adapter, and Flyweight design patterns to optimize request handling and ensure scalability. * Implemented business logic for payment validation, request routing, and enforcing API security policies. * Ensured fault tolerance and implemented retry mechanisms to handle potential banking service failures. Project 6: Developer Blog for Internal Knowledge Sharing: * Developed an internal blog platform to share knowledge among developers at TBC Pay. * Wrote technical blog posts on topics such as: * RabbitMQ & MassTransit for message queuing and integration with microservices. * ASP.NET Request Lifecycle and deep dives into the HTTP pipeline. * Middleware development in ASP.NET Core. * Fostered cross-team collaboration by allowing developers from different teams to contribute, comment, and share insights. Tech Stack Used: * Core Technologies: ASP.NET Core 3.0, C#, Entity Framework, SQL Server, Google Maps API, RabbitMQ, MassTransit, Docker, Kubernetes, RESTful APIs, CQRS, Mediator Pattern, Microservices, Identity & Access Management (IAM). Outcome: * Successfully delivered several high-impact projects, including a microservices platform for payment terminals and a real-time monitoring system. * Contributed to enhancing operational efficiency by designing and implementing secure, scalable, and fault-tolerant systems. * Improved cross-team collaboration and knowledge sharing within the company.

Key Responsibilities: Banking Database & Loan Management System Operations: * Worked extensively with banking databases and loan management systems, specializing in PL/SQL development and Oracle Database 11G. * Implemented PL/SQL solutions for loan refinancing, repayment restructuring, and transaction corrections within the core banking system. * Ensured data consistency and accuracy while managing a high volume of 40-70 daily cases, addressing any inconsistencies and data issues as they arose. Bug Investigation & Resolution: * Identified and analyzed issues such as money leakage, unexpected balance changes, and data inconsistencies. * Collaborated with the development team to create detailed reports and fix core system bugs, ensuring the stability of financial operations. Database Modifications & Enhancements: * Performed critical data updates, schema modifications, and optimizations to stored procedures while maintaining the integrity of the database. * Optimized queries and improved system performance to handle high-volume transactions efficiently. Stored Procedures & Query Optimization: * Developed and maintained complex PL/SQL procedures, triggers, and views for automating banking processes and enhancing system efficiency. * Continuously refined database structures and queries for optimal performance and responsiveness. Big Data Handling & Performance Optimization: * Managed large-scale banking datasets, tuning SQL queries and implementing indexing strategies to improve reporting performance. * Ensured quick and efficient data retrieval, even with massive datasets, to support business-critical decisions. Incident Management & Support: * Investigated and resolved urgent database-related incidents, minimizing downtime and ensuring seamless transaction processing for banking clients. * Acted swiftly to address emergencies and worked cross-functionally to maintain uninterrupted service. Outcome: * Ensured reliable financial data processing by identifying and resolving critical database issues. * Enhanced system efficiency through query optimization, stored procedure management, and schema modifications. * Played a key role in maintaining the integrity and functionality of core banking systems, supporting accurate and timely financial transactions.