● Designed and developed high-performance RESTful & GraphQL APIs using Go (Gin, Echo), optimizing them for high-throughput, low-latency operations, reducing response time by 40%. ● Worked on a High-Load Order Management System using Go / Gin, improving request handling efficiency and ensuring seamless processing of millions of transactions per second. ● Optimized a Golang application to handle 3x the load, implementing Goroutine pooling, database query batching, and optimized caching to reduce CPU and memory consumption. ● Engineered a High-Load Orchestrator Layer in Node.js, optimizing inter-service communication, reducing latency, and ensuring fault-tolerant microservices orchestration. ● Developed and optimized a High-Load Payment System, ensuring efficient, scalable, and fraud-resistant payment processing with secure transaction validation and risk assessment mechanisms. ● Optimized database load by 4x by implementing CQRS, separating databases into readonly and transactional DBs, improving query execution efficiency, and reducing contention on write operations. ● Engaged with the ML team to integrate a Recommendation System, structuring data pipelines, optimizing database design for Python ML models, and ensuring seamless API integrations. ● Handled AWS Tech Stack, deploying and managing applications on AWS S3, EKS, RDS, implementing cloud-native solutions for scalability and reliability while optimizing resource allocation. ● Enhanced observability & incident response using New Relic, Prometheus, Grafana, Splunk, and OpenTelemetry, ensuring real-time monitoring, proactive alerts, and improved system reliability in high-load environments.

● Developed a decentralized NFT marketplace for trading digital assets, including CS:GO skins and in-game items, leveraging Ethereum blockchain and smart contracts. ● Designed and implemented smart contracts using Solidity (ERC-721, Escrow, Auction mechanisms), ensuring secure, trustless transactions while optimizing GAS fees for cost-efficient trades. ● Led the development of a DEX (Decentralized Exchange) based on a Uniswap fork, optimizing liquidity pool mechanics, token swaps, and slippage management to enhance trading efficiency. ● Worked extensively on Web3 integrations, initially using Web3.js and later optimizing for Ethers.js, reducing contract interaction latency and improving gas estimation accuracy. ● Implemented authentication & authorization best practices using JWT, OAuth, and RBAC, ensuring secure access control for marketplace users. ● Secured backend infrastructure by applying TLS, HTTPS, database encryption, and monitoring solutions, preventing unauthorized access and securing user funds. ● Developed and optimized CI/CD pipelines for automated testing, linting, and deployment using GitHub Actions, GitLab CI/CD, and Jenkins, reducing deployment time and increasing system reliability. ● Integrated AWS cloud infrastructure, deploying services on EC2, S3, CloudFront, and RDS, optimizing performance through Redis caching and real-time monitoring with Grafana, Prometheus, and New Relic. ● Worked on blockchain transaction optimizations, minimizing GAS costs by improving contract execution efficiency, leveraging calldata over storage, and optimizing function calls. ● Implemented on-chain and o-chain data synchronization, improving metadata indexing, NFT ownership validation, and transaction history tracking. ● Developed API gateways to facilitate seamless Web3 interactions, enabling smooth transactions between smart contracts and the marketplace’s frontend / backend services.

● Implemented rate limiting and request validation to prevent DDoS attacks, abuse, and system overloads, ensuring high availability and performance stability. ● Optimized SQL queries and database performance, reducing query execution time by 4x through indexing, query restructuring, and partitioning in PostgreSQL, MySQL, and ClickHouse. ● Designed and implemented database replication & horizontal scaling strategies, improving read/write performance and fault tolerance using PostgreSQL, MySQL replication, and ClickHouse distributed clusters. ● Implemented distributed caching mechanisms using Redis and Memcached, reducing database load by 70%, significantly improving response times in high-throughput applications, tested using Yandex Tank. ● Worked extensively on load balancing strategies using Nginx, Kubernetes Ingress, and Rancher, optimizing trac distribution across microservices and reducing request processing time. ● Designed and executed load testing & performance benchmarking, identifying bottlenecks and optimizing system throughput using Yandex Tank, k6, JMeter, and Locust. ● Conducted penetration testing and security hardening, identifying vulnerabilities and implementing OWASP best practices, access controls, and encryption mechanisms. ● Developed and optimized backend services in Node.js, working with NestJS, Express.js, and TypeScript, ensuring high-performance and maintainable architectures. ● Increased test coverage by writing unit, integration, and end-to-end tests using Jest, Mocha, and Chai, significantly improving code quality, reliability, and maintainability.