Apply as Developer Hire Developer

Alex K. Team Lead / Tech Lead / Software Engineer / Blockchain Developer

Blockchain and Cryptography

Summary

- Team Lead / Tech Lead / Software Engineer / Blockchain Developer with 10 years of experience.
- Strong expertise in blockchain development, building decentralized applications (dApps) using Solidity and Rust for EVM and Solana networks.
- Proficient in frameworks like HardHat and Anchor.
- Develop, test, and deploy smart contracts, integrating wallets (e.g., Metamask) and working with DeFi protocols (Uniswap, Aave) and NFT standards (ERC-20, ERC-721).
- Has solid experience in backend development using Django, FastAPI, and SQLAlchemy for scalable APIs and microservices.
- Familiar with CI/CD automation (e.g., GitLab CI/CD, GitHub Actions) and cloud infrastructure on AWS (Lambda, EKS, RDS).
- Skilled in integrating blockchain technologies with backend systems, ensuring code quality through unit testing, fuzz testing, and security audits with tools like RustSec and Slither.

Experience

Team Lead / Software Engineer / Blockchain developer, DEFI ECOSYSTEM HUB

08.2022 - till now

Description: DeFi Ecosystem Hub offers next-generation decentralized finance (DeFi) products built on DeFiChain, a Bitcoin-based blockchain that incorporates native DeFi capabilities.

Responsibilities

  • Collaborated with multiple cross-disciplinary teams and provided technical leadership, guidance, and coaching to engineers through brainstorming sessions, design reviews, and pair programming;
  • Conducted and managed daily stand-ups, sprint planning, retrospectives, and sprint reviews to keep the team aligned and focused on goals;
  • Tracked and reported on key Agile metrics;
  • Blockchain development;
  • Design project architecture;
  • Prepare reports summarizing audit findings and recommendations for improvement;
  • Integration with Wormhole;
  • Integrate with new blockchains and side-chains to increase the multichain infrastructure;
  • Implement buy and burn algorithms;
  • Optimize performance of blockchain applications and smart contracts;
  • Develop smart contracts for various DeFi products;
  • Integrate with decentralized exchanges and other DeFi protocols;
  • Updating and maintaining smart contract code and associated documentation as required to ensure accuracy and adherence to evolving standards;
  • Preparing contracts for security review by conducting necessary testing and organizing relevant documentation in advance of the audit process;
  • Stay up-to-date with the latest blockchain and Python technologies and drive the adoption of best practices with the team;
  • Contribute to high-level architectural decisions for blockchain infrastructure and software systems, ensuring alignment with business goals;
  • Implement EIP-712 for secure and efficient signatures;
  • Implement robust security measures for all smart contracts to safeguard users' assets;
  • Create comprehensive documentation for smart contracts, integration processes, and architecture design;
  • Analyze and refine transaction processing to improve throughput and user experience;
  • Code review.

Environment: Python, Solidity, Hardhat, Solhint, Wormhole, Base, Slither, Mythril, ERC-20, ERC-1155, ERC-721, ERC-721A, EIP-712, Web3.py, Pyth, Subgraphs, Aave, DAO, DeFi Metachain, GitHub.

Tech Lead / Software Engineer / Blockchain developer, PLAY2EARN GAME

08.2020 - 07.2022

Description: Web3.0 application with play2earn mechanics, which is on movement by car. Users owning a car earn standing in traffic, being behind the wheel while traveling, moving a car around the city. Each NFT car owner earns in-game currency, which can be used in-game or cashed in for profit.

Responsibilities

  • Leading the team in making key architectural decisions, such as technology stacks, frameworks, etc.;
  • Collaborate with product owners and stakeholders to refine user stories and clarify backlog items to ensure a clear understanding of project priorities and goals;
  • Led Agile ceremonies, organized and facilitated different meetings;
  • Blockchain development;
  • Conducting security audits using RustSec to identify vulnerabilities and potential risks within dependencies and code;
  • Writing and testing smart contracts using SPL;
  • Development of dApp applications by integrating blockchain technology with gaming mechanics, including tokenomics and NFT assets;
  • Specify and implement consensus mechanism;
  • Developing and optimizing system components for transmitting and receiving payments;
  • Customize transaction execution;
  • Optimize smart contracts for gas efficiency to minimize transaction costs for users;
  • Conduct performance testing and benchmarking of blockchain transactions to ensure scalability;
  • Build custom runtime upgrade mechanisms;
  • Implementing utility tokens;
  • Integrate off-chain data services to enhance gameplay experiences and provide real-time data for in-game events;
  • Implement reward distribution mechanisms for players based on their in-game activities and performance;
  • Building custom metrics and monitoring systems;
  • Functional test of blockchain;
  • Solve security issues;
  • Mentoring new developers;
  • Code review.

Environment: Solidity, Rust, JavaScript, TypeScript, RustSec Cargo, Audit, Rust, Fuzz, Cargo, Solana, Anchor, SPL, EVM networks, Polygon, Uniswap v2/v3, OpenZeppelin, ProxyContracts, GitHub.

Software Engineer / Blockchain developer, INVESTMENT PLATFORM

06.2019 - 07.2020

Description: Platform for investment in digital assets. The De-Fi platform combines a variety of broad functionality that makes it easier to work, the automation of many functions makes the user's work easier.

Responsibilities

  • Close communication with customer and stakeholders to align project goals, ensure transparent progress, and incorporate feedback.
  • Blockchain development using appropriate technologies and frameworks.
  • Blockchain integration into applications, developing APIs and ensuring compatibility.
  • Smart contract development to automate processes, manage assets, and enforce business rules.
  • Custom algorithm development to address specific blockchain requirements.
  • Signature EIP-721 implementation for NFTs.
  • ERC-20 token development.
  • Wallet integration for storing and managing digital assets.
  • Smart contract development for blockchain migration.
  • Mentoring new developers on blockchain concepts and best practices.
  • Code review to ensure quality, identify issues, and enforce standards.

Environment: Solidity, JavaScript, TypeScript, web3.js, Wallets integration(Metamask), EVM networks, Binance Smart Chain, PancakeSwap, Uniswap v2/v3, OpenZeppelin, ProxyContract, Alpaca Finance, EIP-721, ERC-20, GitHub.

Software Engineer, IN-GAME COMMERCE

02.2018 - 06.2019

Description: With the introduction of gComm – the first-ever purchasing platform that lets gamers buy physical products directly inside mobile games – the company pioneered a brand new market category: In-Game Commerce.

Responsibilities:

  • Backend development;
  • Optimizing API performance;
  • Integrate external services with the application
  • Configure Kubernetes (k8s) load balancing;
  • Connect upload to AWS S3 triggers with AWS Lambda;
  • Configuring AWS S3 events publishing to AWS SNS topic;
  • Implement receiving notifications when new file uploaded to an AWS S3 bucket with AWS SNS;
  • Ensuring high performance and adherence to REST principles;
  • Defining roles on IAM;
  • Configure sending an alert on a specific event from AWS CloudWatch with AWS Lambda;
  • Create complex migrations in raw SQL.

Environment: Python, FastAPI, SQLAlchemy, Alembic, Pydantic, Celery, AWS(SQS, SNS, RDS, Lambda, ECR, EKS, API Gateway, IAM, CloudWatch, CloudFormation, etc.), MongoDB, Kafka, GitLab, GitLab CI/CD, Redis, PostgreSQL, ElasticSearch, Docker, Docker Compose, Terraform, Kubernetes(k8s), Pytest.

Software Engineer, LOAN APPLICATIONS BUILDER

09.2016 - 01.2018

Description: Application for creating loan applications. The user creates a loan application, the data about the user and his application are sent to an intermediary (bank). After confirming the user’s data, all information is sent to the bank and a response is expected from the bank.

Responsibilities:

  • Backend development;
  • Building serverless part of application using AWS Lambda functions;
  • Create technical and API documentation that meets required standards;
  • Deploying and managing containerized applications using AWS ECS;
  • Integrate the application with third-party services;
  • AWS S3 configuration for storing images and other files;
  • Scaling and configuring AWS EC2 instances;
  • Monitor SQL server performance using tools and scripts;
  • Create and manage indexes to improve the performance of SQL queries;
  • Write automated tests to ensure quality and prevent regressions.

Environment: Python, Django, Django Rest Framework, Pytest, AWS(RDS, S3, Lambda, EC2, ECS, Cloudformation, Cognito, IAM, etc.), PostgreSQL, Celery, Nginx, GitHub, GitHub Actions, Docker, Docker Compose.

Software Engineer, SMART ADVERTISING PLATFORM

03.2015 - 09.2016

Description: Platform for advertising in mobile applications. The main idea behind the app was dynamic ads based on likes and shares on Facebook. We, together with a team of data engineers, implemented the collection, storage and display of data.

Responsibilities:

  • Backend development;
  • Optimizing API performance and scalability through monitoring, load testing, and performance tuning;
  • Create technical and API documentation using required standards;
  • Implement background serverless calculations with AWS Lambda;
  • Configure AWS S3 triggers with AWS Lambda;
  • Management virtual machines on AWS EC2;
  • Analyzing SQL query performance using query execution plans and optimizing it;
  • Configuring CI/CD pipelines with Jenkins;
  • Writing unit tests.

Environment: Python, Django, PostgreSQL, AWS(EC2, Lambda, S3, API Gateway, RDS, etc.), Redis, Celery, Jenkins, Docker, Docker Compose, Github.

Achievements

Blockchain Performance Optimization

Improved transaction throughput by 25% and reduced latency by 15% through implementation of state sharding and off-chain computation solutions.

Smart Contract Security

Conducted thorough audits and implemented best practices in smart contract development, resulting in a 40% decrease in contract vulnerabilities and a 20% reduction in security incidents.