Vadim Ovcearenco
Verified Expert in Engineering
Software Engineering Developer
Central Athens, Greece
Toptal member since August 22, 2016
Vadim is an accomplished senior software engineer with over 20 years of experience. Vadim has a solid technical background and extensive expertise in both front- and back-end web development, interactive web applications, and more, enabling him to deliver exceptional results across various projects.
Portfolio
Experience
- Software Engineering - 15 years
- Python - 14 years
- Django - 10 years
- NoSQL - 6 years
- JavaScript - 5 years
- Amazon Web Services (AWS) - 5 years
- React - 3 years
- Data Science - 2 years
Availability
Preferred Environment
Git, Vim Text Editor, Linux
The most amazing...
...project I've contributed to involved stream image collecting, processing, and analysis on the AWS and Google platforms using Docker and auto-scaling.
Work Experience
Software Developer (Python/Django/Flask)
Toptal
- Contributed to the development of Hollywood Live, a massively multiplayer mobile project that involved many different disciplines like ultra-low latency live streaming video, Elixir web sockets, and a Django back-end for CRUD tasks and web view.
- Helped build Cobalt Archive, an email/web archive application. The client can archive his/her emails and websites using the web app.
- Worked on Quantified Skin, an app that collects, processes, and analyzes skin photos using AI.
- Helped create the Vroom ADF workflow, which allows the user to create ADF documents based on incoming emails. It provides robust error handling.
Senior Software Engineer (Python)
Kiwi
- Fixed Celery implementation and avoided task duplication. As a result, the team could set up a monitoring tool and significantly decrease the number of errors.
- Added 3D Secure (payment verification) steps to the existing payment workflow.
- Designed and implemented a test environment to test different payment workflows.
- Integrated fraud and risk verification in the payment process.
Senior Full-stack Developer
The Signal Group
- Created a pipeline to fetch data from the clients, process them, and insert them into the internal database.
- Visualized data using Shiny (R language) framework.
- Created a custom authentication plugin for the Shiny framework and deployed the Shiny application on the Azure server.
Senior Full-stack Developer
MoRo Technology Srl
- Integrated HERE WeGo API into the application (back end and front end).
- Created an edit tool for maps to allow a user to add points of interest, paths, and other shapes.
- Built a prediction model for exited data and visualized it on the front end.
Senior Software Engineer, Team Leader
Rebelmouse
- Developed back-end features using Python as the main language. Analyzed requirements, designed architecture, and led the team. Did DSL development, from parsing and compilation to processing.
- Supported the back-end of a CMS, including a custom template language, based on XML syntax, tightly integrated with the data access layer. Extremely extendable on any level (custom tags, custom handers for existed tags, dynamic module loading, custom data models, and custom data access layer).
- Built an image upload tool, using AWS, a REST API on Python, resizing, and a crop tool written in JavaScript (Backbone).
- Developed a central authentication service. As each customer can have several web portals and plays different roles on them, we needed a central authentication service to provide this functionality.
Senior Python/Django Developer
OelandOnline
- Analyzed, designed, developed, and supported the company’s web site in addition to managing projects and creating documentation.
- Built a datagrid widget.
- Created reports.
Senior Software Engineer
oDeskCore
- Developed and maintained large applications (such as managerial tools for maintenance and control of social networks content) following TDD and Agile development.
- Built an operator time tracking system for Facebook.
- Implemented an efficient algorithm to search for bad words in the user's posts, operating up to 10 times faster than a Regex search.
- Created Chrome plugins.
Senior Developer
Cosmorama
- Moved the product, originally written on classic ASP, to .NET. We used XML+XSLT rendering, which allows us to change the .NET version without deep refactoring.
- Employed Backbone.js and AngularJS as a front-end framework.
- Implemented localization in the XML+XSLT transformation.
Lead Software Engineer
Greek Travel Pages
- Created and supported a tourist portal and document workflow application.
- Built a web portal.
- Created reports using XML + XSLT.
- Developed and maintained an MS SQL database.
Senior Software Analyst and Consultant
Actiglobe
- Created and supported an online air ticket reservation system using Galileo.
Experience
Hollywood Live - Quiz Online Game
Role:
System Admin, DB Admin, Web Admin, Back-end Python and Elixir Developer
Technologies:
AWS, NGINX, MySQL, Python, Django, JavaScript, Elixir, Phoenix
Challenges:
We used Elixir/Phoenix to create web socket channels with clients. It gave us best performance and almost no latency.
Primesyft - Contract Management App
Role:
Full-stack Developer
Technologies:
AWS, EC2, RDS, Python, Flask, SqlAlchemy, AngularJS
Challenges:
Find the best AngularJS architecture to provide easy development and updates.
JDM Wealth Management - Cobalt Archive
Role:
Full-stack Developer. I was responsible for email archiving.
All incoming emails should be parsed, inserted in DB and search engine (Elasticsearch).
Challenges:
Create a robust workflow for email processing. User permission access, Effective archive search and management.
Quantified Skin - Skin Analyzer on AWS
Collecting, processing and analyzing skin photos using AWS. The company previously had the project running on GCP.
Role:
As most of the code was written for GCP (by me), I had to migrate to AWS using AWS tools.
Technologies:
EC2, Elastic Beanstalk, Elastic Container Service, Lambda, Auto Scaling, Docker, S3, RDS, SQS, SNS, CloudWatch. CodeCommit, Flask, Ubuntu, JavaScript
Challenges:
Find the best tools in AWS to optimize performance vs. cost. Improve the error handling flow.
Quantified Skin - Skin Analyzer on GCP
Collecting, processing and analyzing skin photos using Google Cloud Platform (GCP)
Role:
I had to design software and hardware architecture to create an API REST interface for the mobile client, to create a minimum-functionality web client using JavaScript libs.
The system should be able to process 6000 photos per hour.
Technologies:
BigQuery, Storage, Datastore, Kubernetes, Google Logging, Compute Engine, Queues, Flask, Ubuntu, JavaScript
Challenges:
To provide required performance, we used Google Container Auto-scaling. All errors are saved in a special queue for processing manually later. The analyzer was run every day and computed all statistical data.
Ivysaur - Flask
https://github.com/perses76/portfolio/tree/master/ivysaurFlask, PostgreSQL, SQLAlchemy
Vroom - Log Analyzer - AWS, Python
https://github.com/perses76/portfolio/tree/master/vroom-log-analyzerGoogle App Engine, Google Storage, Python, AWS, S3
Vroom Doc Flow - Google Cloud
https://github.com/perses76/portfolio/tree/master/vroom-adf-workflowGoogle App Engine, Google Pub Sub, Google Big Data, Python
Kiwi.com - Airline Ticket Booking
http://www.kiwi.comAs a senior software engineer, I implemented the payment module using card payments, Apple payments, and others. The main focus was on system reliability and error handling. My team used an advanced monitoring tool (Datadog) and reports to track all payments.
Education
Master's Degree in Design and Manufacturing of Electronic Devices
Technical University of Moldova - Chichinev
Certifications
Microsoft Certified Database Administrator (MSDBA) on Microsoft SQL Server
Microsoft
Microsoft Certified Application Developer (MCSD) for Microsoft.NET
Microsoft
Skills
Libraries/APIs
React, Pydantic, REST APIs, Vue, SQLAlchemy, Node.js, HERE Maps API
Tools
Celery, AWS SDK, GitHub, Cron, GitLab, Amazon Simple Queue Service (SQS), Vim Text Editor, Git, Amazon Elastic Container Registry (ECR)
Languages
SQL, Python, JavaScript, TypeScript, Elixir, R
Frameworks
Flask, Django, Django REST Framework, RStudio Shiny, OAuth 2
Paradigms
Object-oriented Programming (OOP), Test-driven Development (TDD), Agile Software Development, REST
Platforms
Docker, Amazon Web Services (AWS), Linux, Google Cloud Platform (GCP), AWS Lambda, Amazon EC2, Azure, Kubernetes, Debian
Storage
PostgreSQL, Redis Cache, MongoDB, NoSQL, MySQL, Redis, Redshift, PSQL, Relational Databases, On-premise, Amazon DynamoDB, Microsoft SQL Server, DB, Databases, Datadog, Elasticsearch
Other
Software Engineering, Data Modeling, APIs, API Integration, FastAPI, Back-end, Web Development, Containers, Back-end Development, Data Engineering, Poetry, SDKs, OAuth, Lambda Functions, Amazon RDS, Data Science, Data Analysis, Software as a Service (SaaS)
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