Looking for a job

Денис User

@user512

Message

I build reliable Node.js microservices and blockchain systems for fintech and DeFi.

Spain

Message

At GammaPrime, I build a tokenized private-markets investment platform with around 15 NestJS microservices, designing investment workflows, fine-grained authorization, Kafka-driven notifications, BFF aggregation layers, and real-time chat.

I've also built Solana DEX infrastructure and Web3 mobile-app backends, and at DE.FI developed smart-contract security scanning systems handling roughly 7 million API invocations weekly while improving AWS cost and performance.

Experience

Work history, roles, and key accomplishments

Current

Senior Node.js Backend Developer

Current

GammaPrime

Jan 2023 - Present (3 years 8 months)

Core developer on a tokenized private-markets investment platform, architecting ~15 NestJS microservices with DDD, CQRS, and event-driven patterns over Kafka. Designed RBAC authorization, notifications, real-time chat, and address-book services.

TypeScript NestJS PostgreSQL TypeORM Kafka Redis Socket.IO Docker AWS DDD CQRS Event Driven Architecture RBAC Microservices

Backend Developer

NDA Projects

Jan 2024 - Dec 2025 (1 year 11 months)

Led development of serverless backends for DeFi/Web3 projects, including a Solana concentrated-liquidity DEX indexer and a tap-to-earn mobile app backend. Implemented transaction assembly, authentication, and mining economy features.

TypeScript NestJS Solana Solana Web3 Anchor PostgreSQL Knex Redis MemCached AWS Lambda EventBridge CDK Docker Blockchain Dex Indexer JWT OTP

Software Developer

De.Fi

Jan 2022 - Dec 2024 (2 years 11 months)

Developed and operated DE.FI Antivirus, a distributed smart-contract security scanner analyzing tokens for 100+ vulnerability classes across EVM chains and Solana. Built GraphQL microservices, automated threat-detection systems, and blockchain data pipelines.

TypeScript NodeJS Solidity Python GraphQL Web3 TheGraph PostgreSQL MySQL AWS Lambda AWS ECS Fargate CDK Smart Contract Security Blockchain Microservices Amazon SQS SNS

Blockchain Security Developer

De.Fi

Jan 2021 - Dec 2022 (1 year 11 months)

Performed manual security audits of third-party smart contracts, identifying critical vulnerabilities before mainnet deployment. Contributed to the development of DE.FI Antivirus and blockchain data pipelines.

Solidity Smart Contract Security Audit Blockchain EVM Solana Python TypeScript NodeJS TheGraph AWS

Back-End Developer

Codepeckers

Jan 2021 - Dec 2022 (1 year 11 months)

Built and launched Django backends from scratch for two startup products: a time-tracking platform and a restaurant management tool. Owned the full backend lifecycle including database schema design and REST API development.

Python Django PostgreSQL REST APIs Database Design