Vadim Ovcearenco, Developer in Central Athens, Greece
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Vadim Ovcearenco

Software Engineering Developer

Central Athens, Greece

Toptal member since August 22, 2016

Bio

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

Mellon Direct Solutions
Python, Amazon Web Services (AWS), Kubernetes, Terraform, Docker, Jenkins...
Kiwi
Python, Celery, Google Cloud Platform (GCP), Amazon Web Services (AWS), Flask...
The Signal Group
JavaScript, R, RStudio Shiny, Azure, Python, Linux, Flask, OAuth 2, Poetry...

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

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

Head of IT/Senior Software Engineer

2024 - PRESENT
Mellon Direct Solutions
  • Led the modernization of the company's hybrid infrastructure by introducing AWS, Infrastructure as Code, and CI/CD automation, significantly improving deployment speed and operational reliability.
  • Designed and implemented monitoring and observability solutions using Grafana, Prometheus, and Loki, enabling proactive issue detection across production systems.
  • Automated infrastructure provisioning and application deployments with Jenkins and Ansible, reducing manual operational work and improving deployment consistency.
  • Developed Python automation tools and back-end services supporting business-critical contact center operations running on Windows and Linux platforms.
  • Led a team of five software engineers while remaining hands-on in architecture, back-end development, infrastructure automation, and production support.
  • Improved system availability by implementing standardized deployment processes, centralized logging, and infrastructure automation across multiple environments.
Technologies: Python, Amazon Web Services (AWS), Kubernetes, Terraform, Docker, Jenkins, Ansible, Linux, PostgreSQL, Redis, Grafana, Prometheus, Loki, Git

Senior Python Engineer

2022 - 2024
Kiwi
  • Optimized Celery task execution by eliminating duplicate processing, improving system reliability, and enabling the team to build production monitoring with significantly fewer processing errors.
  • Implemented 3D Secure (3DS) authentication within the payment platform, strengthening payment security while maintaining a seamless customer checkout experience.
  • Designed and implemented a comprehensive testing environment for payment workflows, improving release confidence and reducing regression issues.
  • Integrated fraud detection and risk verification into the payment processing pipeline, increasing transaction security and supporting compliance requirements.
  • Developed back-end services for a high-volume distributed payment platform using Python, Kubernetes, and cloud-native technologies, contributing to reliable and scalable payment processing.
Technologies: Python, Celery, Google Cloud Platform (GCP), Amazon Web Services (AWS), Flask, FastAPI, SQLAlchemy, PostgreSQL, Datadog, Pydantic, Poetry, OAuth 2, SDKs, APIs, API Integration, REST APIs, Docker, Kubernetes, OAuth, Back-end, Test-driven Development (TDD), Web Development, Lambda Functions, GitLab, Containers, GitHub, Redis Cache, PSQL, Relational Databases, On-premise, AWS Lambda, Amazon DynamoDB, DevOps, Amazon Elastic Container Service (ECS), Amazon S3 (AWS S3), Architecture, Full-stack Development, Software Architecture, CI/CD Pipelines, Full-stack, Security, Terraform, Terraform Cloud

Senior Back-end Engineer (Python)

2021 - 2023
The Signal Group
  • Designed and implemented automated data pipelines that collected, transformed, and loaded client data into internal systems, improving data consistency and reducing manual processing.
  • Developed interactive analytics dashboards using R Shiny, enabling consultants and clients to explore complex datasets through intuitive visualizations.
  • Built a custom authentication plugin for the Shiny platform and deployed the solution to Microsoft Azure, providing secure enterprise access to analytical applications.
  • Developed Python back-end services and automation tools supporting data processing, application integration, and cloud deployment across multiple customer projects.
  • Collaborated with consultants and business stakeholders to transform analytical requirements into scalable data processing and reporting solutions.
Technologies: JavaScript, R, RStudio Shiny, Azure, Python, Linux, Flask, OAuth 2, Poetry, SDKs, APIs, API Integration, REST APIs, Docker, OAuth, Back-end, Test-driven Development (TDD), Web Development, Containers, GitHub, Redis Cache, Relational Databases, On-premise, TypeScript, DevOps, Amazon S3 (AWS S3), Architecture, Full-stack Development, Software Architecture, CI/CD Pipelines, Full-stack, Security, Amazon Web Services (AWS), Conda, Jupyter Notebook

Senior Full-stack Developer

2020 - 2021
MoRo Technology Srl
  • Integrated the HERE WeGo Maps platform into a cloud-based application, delivering mapping, routing, and geospatial capabilities across both back-end services and the React front end.
  • Designed and implemented an interactive map editor enabling users to create and manage points of interest, routes, and custom geospatial objects.
  • Developed a machine learning prediction pipeline and integrated its results into the web application, providing real-time visualization of analytical data.
  • Built Python back-end services and REST APIs supporting geospatial processing, secure authentication, and cloud-native deployment on AWS.
Technologies: JavaScript, TypeScript, Node.js, React, Python, Flask, HERE Maps API, FastAPI, Poetry, OAuth 2, SDKs, APIs, API Integration, REST APIs, Docker, OAuth, Back-end, Test-driven Development (TDD), Web Development, AWS SDK, Lambda Functions, Containers, GitHub, PSQL, Relational Databases, On-premise, Amazon RDS, Amazon Simple Queue Service (SQS), Amazon S3 (AWS S3), Full-stack Development, Full-stack, Security, Amazon Web Services (AWS), Jupyter Notebook

Senior Software Engineer, Team Leader

2013 - 2016
Rebelmouse
  • Developed back-end services and core platform features using Python, leading technical implementation from requirements analysis through design, development, and deployment.
  • Extended the CMS back end by implementing a highly customizable XML-based templating engine with dynamic modules, custom tags, and flexible data models.
  • Built an image processing service using Python, AWS, and REST APIs, supporting image uploads, resizing, and client-side editing capabilities.
  • Designed and implemented a centralized authentication service that enabled secure access across multiple customer portals with role-based authorization.
Technologies: Redis, MongoDB, MySQL, Django, Python, SQLAlchemy, SDKs, APIs, API Integration, REST APIs, OAuth, Back-end, Test-driven Development (TDD), Web Development, AWS SDK, GitHub, Redis Cache, Relational Databases, Full-stack Development, Full-stack, Security

Experience

AI-powered Aquarium Design Platform

Developed back-end services for an AI-powered platform that generated custom aquarium layouts using Stable Diffusion. Implemented secure authentication with Auth0, built REST APIs using Django, and managed PostgreSQL databases deployed on AWS. Integrated RunPod GPU infrastructure with ComfyUI by implementing a workflow execution pipeline based on JSON graph definitions, enabling automated image generation from user requests. Collaborated closely with the front-end team to deliver an end-to-end experience from prompt submission to AI-generated aquarium designs while ensuring scalability, reliability, and maintainability of the back-end services.

Autonomous Client Intake SaaS Platform

Developed back-end services for an insurance document automation platform that generated legal documents from structured data. Implemented a template engine based on Microsoft Excel templates, enabling business users to define document layouts without code changes. Built Python services to transform application data into finalized insurance documents, improving automation, consistency, and maintainability of the document generation process.

Commercial Real Estate Financial Modeling Platform

Developed and maintained a commercial real estate financial modeling platform built with Django, MySQL, and AWS. Served as the primary back-end engineer, implementing new features, resolving production issues, and working directly with the client to deliver business requirements. Extended the platform's Excel-based financial modeling engine using PyWin32 and COM automation, enabling dynamic generation and customization of complex financial models based on user input. Improved the maintainability and reliability of the application while supporting its transition from the previous developer and ensuring smooth day-to-day operation.

Hollywood Live - Quiz Online Game

Massive 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 views.

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

Prymesyft is software house specialized in web applications. They needed the app to control contracts, payments, project progress and tasks management for the client.

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

The application to archive email/web data of a client, where the client can create account on the web app and set up what site and what mails he/she wants to archive, and as for the tech stack the folowwing is used, Python, Django, Docker, Amazon SQS, Amazon SNS, Vue.js, Postgres, Elasticsearch.

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

Description:
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

Description:
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.

Education

1993 - 1998

Master's Degree in Design and Manufacturing of Electronic Devices

Technical University of Moldova - Chichinev

Certifications

SEPTEMBER 2024 - SEPTEMBER 2027

AWS Certified Data Engineer – Associate

Amazon Web Services

FEBRUARY 2024 - MARCH 2027

AWS Certified DevOps Engineer – Professional

Amazon Web Services

MAY 2011 - MAY 2012

Microsoft Certified Database Administrator (MSDBA) on Microsoft SQL Server

Microsoft

OCTOBER 2003 - DECEMBER 2012

Microsoft Certified Application Developer (MCSD) for Microsoft.NET

Microsoft

Skills

Libraries/APIs

React, Pydantic, REST APIs, SQLAlchemy, Node.js, HERE Maps API

Tools

Celery, AWS SDK, GitHub, Amazon Elastic Container Service (ECS), Cron, GitLab, Amazon Simple Queue Service (SQS), Terraform, Vim Text Editor, Git, Amazon Elastic Container Registry (ECR), AWS Glue, Amazon Athena, Amazon Elastic MapReduce (EMR), AWS CloudFormation, Amazon EKS, Amazon CloudWatch, AWS IAM, Amazon Virtual Private Cloud (VPC), AWS CodeBuild, AWS Systems Manager, Jenkins, Ansible, Grafana, Loki, ComfyUI

Languages

SQL, Python, JavaScript, TypeScript, Elixir, R, C#, HTML, CSS

Frameworks

Flask, Django, Django REST Framework, Next.js, RStudio Shiny, OAuth 2

Paradigms

Object-oriented Programming (OOP), Test-driven Development (TDD), DevOps, Agile Software Development, REST, ETL, Automation

Platforms

Amazon Web Services (AWS), Docker, Linux, Google Cloud Platform (GCP), AWS Lambda, Amazon EC2, Azure, Kubernetes, Jupyter Notebook, Debian, Vercel, RunPod

Storage

PostgreSQL, Redis Cache, Amazon S3 (AWS S3), MongoDB, NoSQL, MySQL, Redis, Redshift, PSQL, Relational Databases, On-premise, Amazon DynamoDB, Microsoft SQL Server, DB, Databases, Datadog, Elasticsearch, Data Pipelines, Data Lakes

Other

Software Engineering, Data Modeling, APIs, API Integration, FastAPI, Back-end, Web Development, Containers, Back-end Development, Architecture, Full-stack Development, Software Architecture, CI/CD Pipelines, Full-stack, Data Engineering, Poetry, SDKs, OAuth, Lambda Functions, Amazon RDS, Security, Terraform Cloud, Conda, Data Science, Data Analysis, Software as a Service (SaaS), Amazon Redshift, Infrastructure as Code (IaC), AWS CodePipeline, AWS Monitoring, Prometheus, Stable Diffusion

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