Verified Expert in Engineering
Alexander is a software developer with broad knowledge and rich expertise in different areas, mostly blockchain, Python, and Node.js. He works with cutting-edge technologies and is always looking forward to new challenges. Alexander works well in a team or as a single developer.
React Redux, Git, Node.js, Python, Unix, CSS, Vue 3, C++, Sagas, Apache
The most amazing...
...thing I've launched is an initial coin offering (ICO) for SilverToken.
- Added new pages to the Safari web extension that supported secure transaction signing.
- Created and supported Web3 check and safety mechanisms and rules to prevent phishing, scams, and other malicious actions against users.
- Discussed and introduced new APIs and features for Ledger's Web3 check service.
Senior Node.js Engineer
- Supported a payment system that involved complex analytics companion service.
- Maintained an analytics service to collect and combine payment results.
- Supported a payment system while expanding to new markets in Asia.
North American Solar Academy
- Added localization support to the existing back end powered by Django.
- Refactored the legacy Django API, i.e., Django REST service.
- Discussed and suggested new approaches to client-server communication and decreased traffic by 30%, according to the back-end logs.
- Maintained a public website and added new sections and pages.
- Updated and refreshed Swagger API documentation and contract.
- Maintained the Node.js back end with hardened security aspects.
- Added new features to the back end to meet business requirements due to expansion to new markets in Thailand, Indonesia, and the Philippines.
- Supported payment and bonus systems related to different markets and countries.
- Maintained a Strapi-based portal for the marketing team and analytics data representation.
- Maintained the Node.js back end powered by CompoundJS. Supported deployments to AWS Elastic Beanstalk.
- Planned a new API structure, introduced versioning, and added security control.
- Migrated the old code to a modern runtime and added the appropriate fixes to run on the latest version of Node.js.
- Prepared test infrastructure, including deployment, automated testing suite, and test structure.
- Integrated with third-party services and analytics.
- Reworked part of the API to Serverless, including multi-tier AWS Lambda, DynamoDB, and RDS.
- Modernized the AWS deployment approach by adding AWS Lambda for quick operations.
Lead Back-end Developer
- Migrated an old RoR back end to Flask and MongoDB via MongoEngine.
- Added a UI dashboard using Vue and fixed the existing front end.
- Developed an API and protocol for industrial controller data collection.
- Added data exchange between analytics and real-time data-grabbing back ends.
- Built a PostgreSQL database schema and introduced a migration-based approach.
- Added Stripe integration to Vue-based project and corresponding back-end code.
- Improved the dashboard by adding changes to Stripe promotions, such as currency, when applicable.
- Added teacher dashboard controls such as policy and acceptance workflow and user data updates.
- Developed the back end for a custom printing application.
- Planned and implemented database models' design. Added a MongoDB schema migrations infrastructure.
- Added administrative dashboard pages for products, orders, and printers' management.
- Performed the code review and refactored the legacy or invalid code.
- Added a CircleCI automated test and its integration to the app.
- Added automated code linting and testing before committing.
- Managed a unit testing infrastructure with code refactoring (to make it testable) and mocking (to avoid database or third-party services calls).
- Introduced the Elasticsearch integration and reporting.
- Created a reusable chart component and a custom HTML canvas-based chart.
- Reviewed and refactored Vuex structure to make it clear and avoid "magic strings."
- Added a library of wrappers for Vuetify to match project requirements.
Team Leader and Lead Full-stack Developer
- Reworked legacy Express.js code for a set of services on the back end.
- Added a new inter-services communication layer with Autodiscovery.
- Rewrote the administrative dashboard from scratch (increasing performance, providing pagination for large datasets, bug fixing).
- Performed a review of a React-based shop and prepared a list of points to be improved.
- Reviewed the UI and added some pixel works for different screen sizes.
- Added the shopping cart module for the application using reusable React components.
- Refactored Redux-related modules to remove "magic strings."
- Managed weekly meetings and tracked the app development progress.
- Managed the AWS deployment procedure and pipeline automation.
React Native Lead Developer
- Designed an API for remote medical diagnosis to be served from AWS Lambda.
- Created and maintained an API by specs using Python/Chalice.
- Built a React Native client for authentication and API calls.
- Migrated a React Native app to Expo and partially re-implemented a messaging system.
- Added OAuth sign in/sign up to a Lambda-based application.
- Deployed the back and front end to an AWS infrastructure (AWS Lambda, DynamoDB, Route53, and more).
Lead Front-end Developer
San Francisco - Project Evident (via Toptal)
- Supported data extraction and translation from the blogging platform to a custom format.
- Improved the UI/UX of a React-based application.
- Enhanced a Gatsby/Ghost plugin to extract data in an adjusted format.
- Rewrote and optimized GraphQL queries for data fetching.
Lead Full-stack Developer
- Designed and structured the overall project management tool.
- Prepared recommendations on tooling and packages.
- Implemented part of the back end.
- Supervised a team of back and front-end developers.
- Migrated the application UI from Vue-Bootstrap to Vuetify.
- Maintained the application after going to alpha version.
- Created a React Native client for an existing API.
Full-stack and Blockchain Developer
- Prepared architecture and design for a cryptocurrency copy-trading portal.
- Designed an API for a copy trading portal.
- Implemented an API according to specs and hardened it against potential security issues.
- Created a responsive React front end.
- Added real-time Dataflow via WebSockets.
Primebet (Fractional Media)
- Implemented smart contracts from scratch to provide a sports betting feature.
- Optimized Ethereum smart contracts to minimize consumed gas.
- Developed communication between the Ethereum network and the Node.js back end.
- Developed a multi-tier back end to maintain sport games, scores, bidders, and outcome calculation.
- Created a React front end for a sports site.
- Implemented integration with third-party APIs (SportRadar, FantasyData).
- Created background workers to keep data up to date.
- Created deployment procedures and scripts to promote the app to Amazon infrastructure.
MyFocus, LLC (via Toptal)
- Created a distributed file sharing system based on modified BitTorrent/Kademlia protocol.
- Added different network transport layers like UDP4, UDP6, and Bluetooth.
- Redesigned and created file splitting and hashing to promote to network.
- Added file discovery methods and multi-regional support for faster content retrieval.
Senior React/Preact Engineer
404publishing (via Toptal)
- Optimized Preact SSR rendering time.
- Implemented an API to access dynamically changed data.
- Created and maintained the WebSocket communication layer with reconnections, heartbeat, and data consistency check.
- Created and maintained a mesh network based on WebSocket with dynamic node discovering and connection check.
Desktop App Developer
- Designed an API schema and security aspects as a Swagger-based file.
- Developed the desktop application using Qt 4 for end users.
- Added communication to API server with authorization and authentication mechanism.
- Migrated the desktop application to Qt 5 after it was released to production.
- Added client-side data storage, initially JSON, and then migrated to SQLite.
- Supported the app for clients and added new features.
Node.js Back-end Developer
AirBolt (via Toptal)
- Maintained the back end.
- Implemented the database cleanup.
- Reviewed and improved security.
- Reviewed code.
Popchest (via Toptal)
- Provided full-node support and multi-tier deployment support for Bitcoin.
- Fixed Bitcoin-related issues.
- Implemented a new payment feature.
- Implemented tests for Bitcoin and wallets.
Back-end Python Engineer
Successkit.io (via Toptal)
- Supported the Python back end.
- Improved database migration scripts via Alembic.
- Fixed PostgreSQL-specific issues in the database layer.
- Improved and extended existing functionality.
- Added PDF export of reports.
- Extended existing React controls to reflect back-end changes.
SilverToken (via Toptal)
- Implemented smart contracts and tokens.
- Implemented back-end features using Express.js with JWT authentication.
- Tested pre-ICO technology.
- Launched and maintained the ICO.
- Migrated and optimized contracts.
Ethereum and Back-end Developer
OG Mobi (via Toptal)
- Gathered requirements for smart-contract and back-end code.
- Developed a smart contract to collect ether and store jackpot players.
- Built the back end for the site.
- Created a front-end prototype that worked with both the back end and contract events using React.
- Prepared deployment documentation for the site (deployed on Heroku) and Ethereum standalone mode.
- Generated a contract management dashboard.
- Conceived minor specific UI controls for the front end using React, like lottery wheel, carousel, among other playing features.
AirBolt, Pty., Ltd. (via Toptal)
- Enhanced an authentication service in a Node.js application empowered with Hapi.
- Maintained a MongoDB database, fixed consistency, and added constraints.
- Added the administrative part using React for the front end over the existing API.
- Extended the API for the administrative part.
- Prepared deployment and maintenance documentation.
- Refactored and cleaned up the code.
Freelance Full-stack Developer
The Vaan Group (via Toptal)
- Created an audio guide plugin for forms.
- Developed a color search engine that allows users to get images relevant to one or more colors.
- Created image collectors to gather sample data (at least a million images' worth of data) stored in MongoDB from existing images.
- Extended color search engine to allow search by hue value (median).
- Prepared deployment documentation.
Freelance Python Developer
Forecastly (via Toptal)
- Added an Amazon Inbound Shipment fulfillment interface to www.github.com/czpython/python-amazon-mws.
- Supported the site using Flask, Bootstrap, and Flask-Bootstrap packages.
- Refactored and cleaned up code.
- Provided a suggestion for migration from Pony ORM to SQLAlchemy, pointing to potential caveats and bonuses according to the customer's requirements.
Back-end API Developer
- Created an API with OAuth for the existing site to provide desired data externally.
- Secured the API with request rate and IP per minute.
- Developed key infrastructure and UI dashboard to help users maintain access keys and secrets.
- Added automated deployment scripts.
- Maintained existing back-end code and database (PostgreSQL).
- Embedded API intermediate results caching using Redis.
Freelance Lead Python Developer
Pickett (via Toptal)
- Prepared technology stack suggestions. Developed site and database architecture documents.
- Created the site using Python/Flask and MySQL.
- Supported UI according to design guidelines.
- Added a database migration engine and supported multiple database branch migration processes.
- Introduced tests (WebDriver and PyUnitTest) and covered the entire application.
- Appended a data scraper from different sources (HTML pages and APIs).
- Prepared multi-tier deployment documentation and supported automatic deployment to Amazon EC2 instances.
- Optimized Amazon instance performance and cost.
Medify, Ltd. (via Toptal)
- Modified the Anki flashcard app to help users concentrate on their weakest topics.
Senior Python Developer
- Created a UI for user management.
- Developed an engine for static content handling.
- Maintained a back-end application.
- Introduced asset bundling and versioning.
- Implemented a preview of Windows 8 tiles for different modes (cycle, slide, flip, etc.) via jQuery and jQueryUI.
Back-end API Developer
- Assembled API specifications and protocols.
- Set up the environment and automatic deployment script.
- Prepared tests for future API endpoints and methods (integration and unit tests).
- Created an API server according to specs and tests.
- Adjusted the API to meet iOS app requirements.
- Made some change requests to improve application functionality.
- Worked closely with the front-end team to fix issues.
Exigen Services/Return on Intelligence
- Created and maintained the UI for management of client bonus and benefit groups.
- Refactored database structure. Introduced Entity Framework to the application. Fixed bottlenecks in requests.
- Added client-side validation via jQuery validation.
- Maintained unit tests.
- Optimized SQL scripts.
- Implemented a thick client.
- Provided coverage for unit tests.
- Reviewed code.
- Developed Asterisk modules.
- Introduced logging via a logging application block.
Based in Singapore, Ox Street aims to connect buyers and sellers across the region. This marketplace makes it easier for clients to buy what they want without waiting weeks, paying crazy shipping fees, and getting ripped off by fakers.
Ox Street believes South East Asia is the next frontier for street culture. Influenced by local cultures, East Asia and the West are blending together to create a unique and highly innovative street culture movement. Ox Street is the core connector and facilitator of this movement.
Technologies used in the implementation process include Node.js 10, MySQL, and Vue with Vuetify.
Demo credentials: firstname.lastname@example.org / P@ssw0rd and email@example.com / P@ssw0rd
Real Estate Reporting and Forecast System
I developed C# code for the project.
Health and Benefits Bonus System
I implemented it as the technical leader, using C#, DataFlux, and WebForms technologies.
Share/Repost JS Widgetshttps://www.rhythmone.com/
a sharing widget that supports link shortening and user action analytics (known before as Po.st, now retired).
React Native, Truffle, Alembic, Qt, Django, Flask, Express.js, Vuetify, Vue SSR, Redux, Serverless Framework, Qt Quick, Durandal, Bootstrap, Knockout (Knockout.js), Hapi.js, Boost, NestJS, Jest
React Navigation, React, React Redux, Flask-RESTful, Node.js, SQLAlchemy, Vuex, Vue, Kivy, Asyncio, PyQt, Redux-Saga, React Router, Vue Material, Stripe, Preact, PyMongo, jQuery, Amazon MWS, REST APIs, Web Audio API
Expo, Qt Creator, GitHub, Redux Thunk, Amazon ElastiCache, Amazon Elastic Container Service (Amazon ECS), Basecamp, Git, Auth0, Webpack, Kue, Ghost, GTK+, Amazon Elastic Container Registry (ECR), Apache, Mongoose
RESTful Development, REST, Unit Testing, Lambda Architecture, Serverless Architecture, Object-oriented Design (OOD), Waterfall Development, Concurrent Programming, Functional Programming, Agile Software Development, Distributed Computing, Microservices
AWS Lambda, Amazon Web Services (AWS), Blockchain, Ethereum, Linux, Firebase, Win32, Windows, Unix, Oracle, Amazon EC2, Heroku, Docker, Netlify, Kubernetes
PostgreSQL, NoSQL, MySQL, MongoDB, PostGIS, Elasticsearch, Microsoft SQL Server, MongoEngine, Amazon S3 (AWS S3), Redis, LevelDB, CouchDB, SQLite
Gatsby, Sagas, Code Architecture, Solution Architecture, ICO, DApps, Tornado, Vue-router, Vue 3, Strapi, Architecture, Apollo Server, Serverless, Cryptography, Push Notifications, Caching, Bitcoin, PDF, APIs, Prototyping, API Design, Smart Contracts, Online Payments, Cryptocurrency, Trading, Cairo, Aiohttp, WebSockets, ECS, ECharts, Apollo, Data Migration, Software, Geolocation, Safari Extensions
Bachelor's Degree in Computer Science
Saint Petersburg State University - Saint Petersburg, Russia
Engineer's Degree in Radio Systems
Saint Petersburg State Electrotechnical University - Saint Petersburg, Russia