Vladimir Kravchenko
Python Developer in Playa del Carmen, Mexico
Member since June 18, 2016
With a strong scientific background, Vladimir knows how to operate around tricky problems and chases quick and elegant solutions for them. He's a generalist, always striving to use the best-suited technology for each project instead of always gravitating to the most well-known one. He is also dedicated to pixel-perfect solutions and integrates well with either a front-end or back-end team.
Vladimir is now available for hire
Portfolio
- Toptal ClientNode.js, React, Meteor
- Palco, Inc. (via Toptal)React, Elixir, Phoenix, SQL
- BettyBlocks (via Toptal)Elixir, Ruby, PostgreSQL, OTP
Experience
- Data Analysis, 9 years
- Python, 8 years
- Functional Programming, 7 years
- JavaScript, 6 years
- Node.js, 4 years
- React, 3 years
- Meteor, 3 years
- Elixir, 3 years
Availability
Full-time
Preferred Environment
*nix, JetBrains WebStorm, Sublime Text, Git
The most amazing...
...project I've made was 3D planning software to minimize the effective dose of human radiotherapy cancer treatment, using Monte Carlo methods.
Employment
Meteor Developer
2018 - 2019Toptal Client- Migrated client profile and client enrollment management to React.
- Helped to create a new GraphQL API instead of an elder REST API.
- Modified a surveying app to the new external API version.
- Implemented a separate feature to extract data from uploaded files and send it to an external API.
- Supported existing production application as well as fixed bugs and issues.
Technologies: Node.js, React, MeteorFull-stack Developer
2017 - 2019Palco, Inc. (via Toptal)- Created an application to enroll new workers or participants using React and Phoenix framework.
- Created a timesheet management application using React and Phoenix framework.
- Created a dashboard application for internal managers to process data from other applications.
- Integrated a document management system into the enrollment application to support e-doc to paper conversion.
- Optimized SQL data storage and querying to get around five times faster response from complex data requests.
- Automated data validation and reports.
Technologies: React, Elixir, Phoenix, SQLElixir Developer
2016 - 2017BettyBlocks (via Toptal)- Implemented major parts of the new back-end. Included core features and external service integrations.
- Helped to rewrite a custom language parser from Ruby to Elixir implementation (complete feature compatibility).
- Optimized data processing to simulate object mutations using functional paradigm using ETS cache.
- Supported implementing and testing full-feature parity between new and old back-end applications.
Technologies: Elixir, Ruby, PostgreSQL, OTPSenior Engineer
2015 - 2017Urban Capital, Ltd.- Developed a search engine website using Meteor (Node.js + Blaze) and Google Maps for the front-end.
- Made web crawlers to scrape and parse real estate sites using Python's ScraPy and NTLK (natural language processing).
- Optimized a single-page application for search engines (SEO).
- Created a tool to analyze properties and estimate prices. This tool also allows for price predictions based on multiple parameters and statistics.
- Made a web crawler to parse popular Facebook posts and see the engagement on a selected theme (Selenium and Python's Newspaper).
- Created a dashboard to manage users and data including geolocation data.
Technologies: Node.js, Python, Meteor, HTML, CSS, Selenium, MongoDBMeteor Developer
2015 - 2016Fujikon Industrial Holdings, Ltd.- Optimized the Meteor+React-based chat app for 2000+ simultaneous connections.
- Implemented email notifications for the above app.
- Added an integrated TODO module.
- Added a file-uploading module.
Technologies: Node.js, React, MongoDB, Meteor, Nginx, LDAPSenior Engineer
2015 - 2015Sliday- Added back-end logic to designs provided.
- Set up the server with an automatic deployment.
- Consulted a team of developers on architecture, DevOps, and development.
- Set up the JS front-end to manage REST API appointments.
- Implemented an email notification system.
Technologies: Ruby on Rails, PostgreSQL, jQueryWeb Developer
2014 - 2015CTM, Ltd.- Made a solution for high-load server-server queues communications with , ~10,000 daily users, up to 3GB per file.
- Integrated the solution with Russian customs.
- Set up a remote server machine to host the application and queue.
- Created a notification system to check project availability with SMS notification on Python.
- Added a load balancer daemon to manage old SMTP- and new WebSphere-based services.
Technologies: Python, PostgreSQL, IBM WebSphere, C++, SVNSenior Developer, Co-founder
2014 - 2015Fcuking Easy CRM- Created a sales CRM system from the ground up. Currently, over 100 companies are using it.
- Developed an online mail client to integrate deals with email threads using Gmail API.
- Led a team of five, managing the tasks for both designers and developers.
- Optimized project APIs to be ten times faster than using a basic Ruby on Rails solution using Rake, Grape, and EventMachine.
- Created scripts for automatic deployment, backup, tests, and automated availability reports.
Technologies: Ruby on Rails, Ruby, EventMachine, GMail API, HTML, CSS, Angular JS, PostgreSQLSenior Assistant Engineer
2011 - 2014Scientific Research Institute of Blood Circulation Pathology- Created verification software to estimate the precision of a 3D 'effective dose' distribution in the human body using computer modeling.
- Created a tool to recreate chemical data from computer tomography (DICOM) and insert it into modeling software.
- Created a computer model of a medical linear particle accelerator with rotation and moving collimators (filters).
- Simulated a real treatment process based on CERN's data of the passage of particles through matter. GEANT4.
- Created a disturbed calculations system for treatment simulation.
- Conducted experiments on the real device to calibrate the computer model.
Technologies: C++, GEANT4, DICOMSenior Assistant
2010 - 2011Budker Institute of Nuclear Physics- Created an “effective dose” calculation software for different human exposure inspection projections on X-ray inspection devices.
- Analyzed estimated data for different projections to improve the inspection device. One such device is used at Tolmachevo International Airport.
- Migrated the Linux-based calculation software to Windows.
- Conducted experiments on the real device to calibrate the computer model.
- Published a paper based on estimations and data analysis.
Technologies: C++, GEANT4
Experience
- Urban Search (Development)
An Australian data-driven real estate search engine. I've been working in a team of three on both back-end and front-end development.
Every building was rated and scored depending on various data sources like geolocation data, historical significance, etc. NLP also works on the front-end part of the project, making free text search possible (e.g., You can simply type: "I want a two-bedder with high ceilings and water views in Bondi" and the results will appear). - Fcuking Easy CRM (Development)https://feasy.me/
A featherlight weight CRM system concentrated on sales productivity and built with 4 core principles in mind:
- Touch-move rule (like in Chess but for communications)
- You need to write down everything (memory is the key)
- Woodpecker sales (write-call-meet till you make it)
- Time only priority
Based on those principles, a salesperson can proceed with several hundred deals simultaneously.
From the technical side:
- AngularJS front-end
- Ruby EventMachine REST API back-end
- PostgreSQL as a database
- Redis for background tasks - TimeWalla (Development)
A Ruby on Rails project to schedule appointments.
Originally for USA barbershops network. The point is to adjust schedule dynamically, depending on client's, if somebody's running late or otherwise want to move earlier. and keep both customers and workers updated.
Skills
Libraries/APIs
Gmail API, Node.js, React, EventMachine, Facebook API, Ractive.jsParadigms
Model View Controller (MVC), REST, Data Science, Test-driven Development (TDD), Object-oriented Programming (OOP), Search Engine Optimization (SEO), Functional ProgrammingPlatforms
Meteor, Amazon Web Services (AWS), WebSphere MQ, OTPOther
Creative Problem Solving, Customer Relationship Management (CRM), Self-starter, Single-page Applications (SPA), Data Analysis, Minimum Viable Product (MVP), OAuth, Startups, Data Scraping, Natural Language Processing (NLP)Languages
ECMAScript (ES6), Python, HTML, CSS, Elixir, Ruby, JavaScript, Erlang (OTP), GraphQL, C++Frameworks
Bootstrap 3+, Phoenix, Ruby on Rails (RoR), Machine Learning, AngularJS, ScrapyTools
Git, Adobe Photoshop, Sketch, Sublime TextStorage
MongoDB, PostgreSQL, NoSQL
Education
- Master's degree in Physics and Technology2011 - 2013Novosibirsk State University - Russia, Novosibirsk
- Bachelor's degree in Physics and Technology2007 - 2011Novosibirsk State University - Russia, Novosibirsk
