Location
UkraineRate
$30
/ per hour
Years of experience
7+About
As an Expert Backend Developer at Nuant since April 2022, I have been deeply involved in developing and maintaining microservices using Nest.js and web3. My work primarily revolves around creating a data provider from different blockchains, leveraging a tech stack that includes Node.js, TypeScript, Docker, PostgreSQL (TimescaleDB), Redis, MongoDB, and Kubernetes. My key responsibilities have included developing a microservices architecture with a team of backend developers, implementing custom JSON RPC calls and API Gateways for fetching blockchain data, and developing real-time updates and payment microservices supporting Stripe, Coinbase, and BitPay. Additionally, I have focused on fetching data from DeFi protocols, calculating analytics, and ensuring efficient caching mechanisms with Redis and MongoDB. Previously, as a Senior/TL Backend Developer at Opinov8 from September 2019 to April 2022, I was responsible for developing and maintaining various projects under NDA, with a focus on microservice architectures and serverless infrastructures using Node.js, AWS Lambda, and other technologies. My role included creating authorization microservices, optimizing performance with TypeORM, conducting design and code reviews, and mentoring junior developers. I also implemented integrations with AWS services, real-time tracking systems, caching mechanisms, and payment integrations with Stripe. My experience at Opinov8 also involved developing serverless architectures, handling asynchronous messaging with RabbitMQ, and implementing real-time support and notifications systems.Tech Stack
Backend, Amazon S3, AWS, Azure, Docker, GraphQL, JavaScript, Kafka, Kubernetes, MongoDB, NestJS, Node.js, PostgreSQL, Redis, Typescript, Web3Experience
- At Nuant, developed and maintained microservices using Nest.js and web3, including creating a microservices architecture with a team of backend developers.
- Designed custom API Gateways and implemented JSON RPC calls for efficient blockchain data fetching, incorporating hot/cold cache layers with Redis and MongoDB.
- Implemented real-time updates using WebSocket-like subscription mechanisms and developed a real-time tracking system using Google Maps.
- Developed payment microservices supporting multiple payment methods, including Stripe, Coinbase, BitPay, Apple/Google Pay, and MasterCard, ensuring secure and seamless transactions.
- Created serverless infrastructures using AWS services such as Lambda, API Gateway, and DynamoDB, deploying applications through AWS CDK and CloudFormation.
- Developed microservices for fetching data from DeFi protocols, processing job queues, and calculating user analytics from this data.
- At Opinov8, responsible for mentoring middle and junior developers, conducting design and code reviews, and optimizing performance using TypeORM and other technologies.
Employment history
Expert Backend Developer, Nuant
April 2022 - Present
- Implemented a custom JSON RPC calls for web3
- Implemented a custom API Gateway for fetching blockchain data (like blocks, transactions, traces, logs etc) with hot/cold cache layers using Redis and MongoDB.
- Implemented real-time updates using WebSocket-like subscription mechanism.
- Implemented a microservice for fetching data from DeFi protocols (using job queue) and calculating analytics for users from this data.
- Implemented a payment microservice that supports Stripe, Coinbase, BitPay payment methods.
Senior/TL Backend, opinov8
September 2019 - April 2022
- Developed domain-oriented microservices architecture for this project in a team of 7 backend members, using NestJS built-in microservices support (transports HTTP, RabbitMQ, WebSocket)
- Created data models and optimized performance using typeorm (for example simplify legacy relationships between data models).
- Design and code reviews.
- Mentoring Middle/Junior devs.
- Implemented: 2FA mechanism using nodemailer, some AWS (S3, RDS(postgres), SNS) integrations, demo-mode for new users, payment integration with Stripe, real-time support for users, a real-time tracking system using Google Maps, caching mechanism using Redis, asynchronous global system updates/events using RabbitMQ (fanout exchange)
Senior Backend Developer, Software
January 2021 - July 2021
- Developed microservices and implemented integrations between them
- Implement caching mechanism using Redis
- Store data in Azure CosmosDB
- Implement request/response sign/verify operations between microservices and user encrypt/decrypt operations using Azure Key Vault
- Implement Saga(orchestrator) pattern between microservices
- Implement asynchronous messaging using Azure Service Bus (implement own Azure Service Bus transport integration using @nest.js/microservices package)
- Implement payment (Apple/Google Pay, MasterCard) integration using UPC(Ukrainian Processing Center) API
Backend Node.js Developer, SafeSwiss
October 2018 - September 2019
- Developed microservices and implemented integrations between different
microservices using REST + WebSocket + RabbitMQ communications - Created and optimized SQL tables + queries using knex ORM
- Developing security solutions (for example I implemented self-made DDos protection using
Redis) - Design and code review
- Worked with encryption and related technologies OpenPGP, DHKE, RSA
FullStack Node.js Developer, Freelance
November 2017 - October 2018
- Developed a monolithic application and frontend for it in a team of 4 freelance developers
- Implemented authorization flow using Redis for Session management, store data using PostgreSQL, some logistic and asynchronous updates using websockets
Education history
National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”
2017 - 2021
Faculty of Applied Mathematics Bachelor of Computer Engineering