vmarkvardt

Development of a decentralized Layer 1 blockchain infrastructure for transactions, data streaming, storage, and smart contract execution. Highlights: - Delivered 15+ features and resolved 50+ issues in blockchain node infrastructure, contributing to 97.9% uptime and smoother testnet deployments. - Improved core C++ and Node.js nodes, reducing average API response latency by 25%. - Maintained and extended SDKs in C++, Go, and TypeScript to support third party integrations, adding support for new transaction types and improving developer onboarding. - Created and enhanced REST and WebSocket APIs for communication between system components, added 10+ endpoints enabling reliable inter-service communication. - Designed and built internal developer tools for testing various layers of the blockchain stack used by 3 teams. - Built a Vuejs based frontend for decentralized storage interaction, enabling file uploads/downloads with <500ms average latency. - Optimized MongoDB interactions for collections with 5M+ records, reducing query times by 70% through pagination and indexing. - Setup MXE based cross-compilation for Windows/Linux targets, reducing manual setup time by 70% and integrating with CI pipelines(Jenkins). - Focused on performance, scalability, and developer experience across infrastructure components. - Mentored 4 junior devs over 6 months, improving code quality and reducing PR rejection rate by 30%.

Developing Navigation Controller for premium car brands, microservices for navigation controller, automation tests. Highlights: - Developed an internal testing utility in C++/Qt with MQTT support, used by 2+ teams for validating service communication; reduced manual testing time by 30%. - Improved sync performance by 2x through optimized indexes and prepared SQL queries, reducing average DB response time from 900ms to under 400ms for 500k+ records. - Improved Elasticsearch stability by tuning Docker limits and JVM config, reducing out of memory crashes by 90% and maintaining 99.9% uptime in production. - Built a working prototype within 2 weeks during a cross-team workshop, enabling integration with 2 external services to enhance vehicle navigation and POI search experience. - Mentored 1 junior developer, reviewed 100+ PRs over a year; helped reduce code defects by 20% and accelerated onboarding time by 30%.

Development and support of a database management system the Valentina Studio and the database Valentina, Valentina Server. Highlights: - Developed a converter from SQLite to VDB format, enabling migration of 100+ tables with millions of records; improved performance 2x compared to previous solution. - Implemented Excel import/export with image support, handling files up to 1M rows; reduced manual report generation time by 60%. - Integrated and customized third party Excel I/O library across 3 modules; fixed 4+ critical bugs and reduced export failures by 95%.