Created Solidity smart-contracts for custom business logic (with ERC-20 token under the hood), deployed it on different blockchains, used OpenZeppelin libraries for safety development. Used third-party web3 technologies (like deBridge and other contracts) for interacting with them. Transferred tokens and other data cross-chain with decentralized bridges. Have optimized process for decreasing gas usage and aggregated data to pay lower commissions. Made JS requests to blockchain to retrieve data about events and call smart-contract functions. Used technologies: Solidity, JS, Hardhat, OpenZeppelin, Assembly, deBridge, MetaMask, EVM, Ethereum, BNB, etc.

In a short time studied the company's technology stack, designed the architecture of a new internal product, and successfully implemented an MVP. Designed an easily scalable framework based on a plugin system, which will save a lot of man-hours of development in the long run. Technically led the team, consisting of 5 dev specialists, did code reviews, communicated with other Ozon teams to have an integration.Used technologies: Golang, gRPC, Graphql, Kafka, PostgreSQL, microservice architecture, Docker, k8s, Service mesh, client-side load balancing, Patroni, etc.

Designed and developed the back-end of a new product for bus monitoring in real time and fare payment by mobile application with more than 300k DAU. Have scaled the system to connect in several cities. Led development team. Invited new employees and mentored them. Communicated with technical teams of partner companies in different cities to build the interaction of systems. Developed distributed algorithm for constructing the most optimal routes using public land transports, which can compete with the Yandex maps builder. Improved internal architecture of services for easier scaling which reduced 30% of company’s expenses.Used technologies: Golang, REST, GraphQL, NATS, gRPC, Protobuf, PostgreSQL, ClickHouse, Redis, Gin-gonic, microservice architecture, Docker, Kubernetes, Ansible, Sentry, Kibana, etc. ------Developed computer vision postprocessing module for 3D camera Intel RealSense in a RnD project for further transmission to a neural network. The camera is inside a bus and counts the number of passengers.Used technologies: Golang, C/C++, Cgo, OpenCV, Intel RealSense SDK, ARM, NanoPi M4, etc.

Developed back-end API, front-end and database structure for a system that let users manage cameras in real time, check a person’s profile, observe this person through a camera and interact with the face-detection system. Delivered MVP of product in a short time and got positive feedback after the release. Changed the way of drawing objects on the map, increasing the performance by 40% on the client-side. Mentored 1 junior developer.Used technologies: Back-end: Java, Spring; DB: PostgreSQL, PL/pgSQL; Front-end: JavaScript, VueJS, Mapbox, Canvas, Datatables.-------Worked as a part of the back-end development team, designed and built back-end API for a taxi driver control project, where administrators can monitor taxi drivers on a map and check statistics of each driver. Interact directly with API of the device in the car.Used technologies: Java, Spring, IoT, PostgreSQL, PL/pgSQL, etc.