Oleh – Django, React, Typescript, experts in Lemon.io

Oleh

From Ukraine (UTC+3)flag

Full-stack Web Developer|Strong senior
Lemon.io stats
2
projects done
420
hours worked
1
ongoing project

Oleh – Django, React, Typescript

Senior Full-Stack Developer & Team Lead with 10 years of experience in Python/Django, React, TypeScript, PostgreSQL, and AWS. Oleh boasts strong background building and scaling multi-tenant SaaS platforms, real-time systems, and enterprise solutions across fintech, education, logistics, CMS and cloud infrastructure. He led the development of a global backup & disaster recovery platform for 20,000+ businesses and a logistics platform with live tracking and route optimization.

11 years of commercial experience in
Administration
AI
Automotive
Business intelligence
Cybersecurity
Data analytics
Logistics
Management
CMS
CRM
Mobile apps
SaaS
Web development
Main technologies
Django
1 year
React
1 year
Typescript
1 year
Python
1 year
FastAPI
1 year
Additional skills
Node.js
PostgreSQL
Kubernetes
ElasticSearch
AWS
Stripe API
REST API
MongoDB
Docker
Tailwind CSS
Express.js
Material UI
Django REST
CI/CD
Amazon S3
AWS Lambda
OpenAI API
Direct hire
Not possible
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Experience Highlights

Back-end developer, Team lead
May 2026 - Jul 20262 months
Project Overview

AI-powered SaaS platform for automotive dealerships that scores vehicles 0-100 from Carfax, Experian AutoCheck, JD Power ChromeData, Black Book, and Manheim MMR data to deliver a Buy / Caution / Pass verdict, sharpened over time by a proprietary scoring model.

Responsibilities:
  • Led a team of 3 engineers, driving product and technical-roadmap decisions that kept the V1 build scoped and on schedule.
  • Designed and delivered the platform's full authentication and identity system - Auth0 integration, secure token handling, user lifecycle, invitations, and onboarding.
  • Built the multi-tenant organization and dealer-profile system forming the core data model for every dealership, rooftop, and user.
  • Delivered end-to-end user management with granular roles, permissions, and audit logging across complex dealership hierarchies.
  • Built the Condition Assessment scoring engine and automatic photo-attachment pipeline feeding the AI verdict.
  • Built a real-time dealer financial dashboard (inventory health, floor-plan exposure, role-gated gross-profit visibility) and owned the auction-data integration powering the platform's Auction Command Center.
Project Tech stack:
Python
FastAPI
PostgreSQL
Redis
Celery
LangChain
LangGraph
AWS
Auth0
React Native
Stripe API
JWT
Claude LLM
Terraform
Docker
Full-Stack developer, Team lead
Aug 2024 - May 20261 year 9 months
Project Overview

Cloud-based platform for a managed Backup-as-a-Service (BaaS) and Disaster-Recovery-as-a-Service (DRaaS) provider serving enterprise clients across multiple compliance frameworks (SOC 2, ISO 27001, PCI-DSS, HIPAA). The platform enables customers to manage backup policies, monitor backup jobs in real-time, perform data restores, configure disaster recovery orchestration, and manage subscriptions across multiple product lines (Veeam-powered BaaS/DRaaS, endpoint backup, SaaS backup, and server backup). Has a multi-tenant architecture supporting 20,000+ businesses globally with geo-redundant data centers across North America, Europe and Oceania.

Responsibilities:
  • Architected a multi-tenant SaaS platform serving 20,000+ businesses across 3 continents, with geo-redundant data centers in North America, Europe, and Oceania.
  • Engineered REST APIs supporting 4 product lines (Veeam-powered BaaS/DRaaS, endpoint backup, SaaS backup, server backup) with SOC 2, ISO 27001, PCI-DSS, and HIPAA compliance.
  • Built a real-time monitoring system using WebSockets delivering live backup job progress and system health notifications to enterprise clients and support teams.
  • Implemented an RBAC system supporting 4 user roles (end customers, MSP administrators, support staff, compliance auditors) with granular permission controls.
  • Developed a partner/MSP portal enabling white-label branding and multi-client account management, generating a 30% increase in partner adoption.
Project Tech stack:
Django
React
Node.js
PostgreSQL
MongoDB
GraphQL
Vmware
AWS
Python
Kubernetes
OAuth
Stripe API
Redis
ElasticSearch
RabbitMQ
REST API
Full-Stack developer
Jul 2023 - Sep 20241 year 2 months
Project Overview

Comprehensive fleet management and logistics CRM platform enabling transportation companies to manage their entire fleet operations, optimize delivery routes, track vehicles in real-time, and streamline dispatch operations. The system serves logistics companies managing 50-500+ vehicles, providing end-to-end visibility from order intake through delivery completion. Built with geospatial capabilities for route optimization, real-time GPS tracking, driver management, fuel consumption monitoring, maintenance scheduling, and automated customer notifications. The platform integrates with telematics devices, supports multi-depot operations, and provides predictive analytics for delivery time estimates, route efficiency, and operational cost optimization.

Responsibilities:
  • Designed and developed REST APIs endpoints for fleet management, route planning, order dispatch, driver assignment, vehicle tracking, and customer portal functionality.
  • Built responsive web dashboard for dispatchers featuring real-time map view with live vehicle positions, route visual* Designed and developed REST APIs for fleet management, route planning, order dispatch, driver assignment, vehicle tracking, and customer portal functionality.
  • Built a responsive dispatcher dashboard with real-time map view, live vehicle positions, route visualizations, and delivery status updated via WebSockets.
  • Implemented an intelligent route optimization engine (Google OR-Tools + custom algorithms) factoring in vehicle capacity, time windows, traffic patterns, and delivery priorities.
  • Developed real-time vehicle tracking integrating GPS telematics devices (Geotab, Samsara, Verizon Connect) to capture location, speed, fuel consumption, and diagnostics.
  • Built an AI-assisted dispatch suggestion engine (LangChain) and natural-language delivery exception reports (OpenAI API) to reduce manual log review.
  • Developed analytics dashboards for fleet utilization, on-time delivery rates, and route efficiency, plus predictive ETA calculations using ML models.izations, traffic overlays, and delivery status indicators updated via WebSockets.
  • Implemented intelligent route optimization engine using Google OR-Tools and custom algorithms to calculate optimal multi-stop routes considering vehicle capacity, time windows, traffic patterns, driver hours, and delivery priorities.
  • Developed real-time vehicle tracking system integrating with GPS telematics devices (Geotab, Samsara, Verizon Connect) to capture location data, speed, fuel consumption, idle time, and vehicle diagnostics.
  • Integrated OpenAI API to generate natural-language delivery exception reports, surfacing route anomalies and delay patterns for dispatchers without requiring manual log review.
  • Built an AI-assisted dispatch suggestion engine using LangChain that recommended optimal vehicle-driver assignments based on historical performance, load type, and real-time conditions.
  • Created interactive map interfaces using Mapbox GL JS and Leaflet for route planning, geofencing, territory management, and visualizing historical route data with playback capabilities.
  • Implemented automated route recalculation and dynamic routing to handle real-time changes including new urgent orders, traffic delays, vehicle breakdowns, and driver availability changes.
  • Created order management system with features for shipment creation, customer address validation, delivery time window scheduling, multi-stop consolidation, and load planning optimization.
  • Implemented geofencing functionality for automated arrival/departure detection at customer locations, depot check-in/check-out, and restricted zone alerts triggering notifications to dispatch and drivers.
  • Developed analytics dashboards providing insights on fleet utilization, on-time delivery rates, fuel consumption trends, driver performance metrics, route efficiency, and cost per mile calculations.
  • Created dispatch console for operators to manage daily operations including order assignment, driver scheduling, vehicle allocation, route approval, exception handling, and real-time communication with drivers.
  • Implemented predictive ETA calculations using machine learning models analyzing historical route data, traffic patterns, time of day, weather conditions, and driver behavior to provide accurate delivery time estimates.
  • Built maintenance management system with scheduled maintenance tracking and automated service.
Project Tech stack:
Django
Python
React
React Native
Typescript
Node.js
Express.js
PostgreSQL
MongoDB
Redis
MapBox
WebSocket
Docker
Kubernetes
AWS
ElasticSearch
RabbitMQ
Chart.js
Material UI
Tailwind CSS
Terraform
Stripe API
OpenAI API
LangChain
Full-Stack developer, Team Lead
May 2020 - Jun 20233 years 1 month
Project Overview

Software agency, specializing in building high-quality mobile and web applications using modern JavaScript technologies. Experience ranges from consumer apps and IoT-connected products to fintech and Web3 platforms, enabling us to support both startups and established companies in launching and scaling their products.

Responsibilities:
  • Managed relationships with clients, specifically with English-speaking customers, understanding their needs and delivering tailored software solutions.
  • Mentored a team of developers of 10 people fostering a collaborative and productive work environment.
  • Oversaw the planning, execution, and delivery of software development projects, ensuring they met quality standards and deadlines.
  • Actively participated in the development process, contributing to both front-end and back-end solutions.
  • Implemented best practices and standards to ensure the delivery of high-quality software products.
  • Participated in effective staff supporting and supporting clients’ end-users, enhancing satisfaction and loyalty.
Project Tech stack:
JavaScript
React
Redux
HTML
CSS
Docker
AWS
CI
CD
Django
Django REST
FastAPI
PostgreSQL
Redis
MongoDB
Celery
RabbitMQ
Full-Stack Developer
Sep 2016 - May 20203 years 8 months
Project Overview

Web development agency specializing in building custom websites and digital platforms using Python, Django, JavaScript, HTML/CSS, and responsive front-end frameworks. The company focuses on creating business-oriented web solutions with integrated CMS, SEO, and ongoing server hosting/administration support. BergSoft+ works across niches such as e-commerce, corporate websites, service portals, and marketing-driven web tools, prioritizing performance, usability, and long-term maintainability.

Responsibilities:
  • Built  server-side  logic  and  database  interactions  to support application functionality.
  • Implemented user interfaces with HTML, CSS, and JavaScript, ensuring responsive and user-friendly designs.
  • Created and maintained RESTful APIs for seamless communication between front-end and back-end systems.
  • Wrote unit and integration tests, and performed debugging to ensure software quality and reliability.
  • Managing deployment processes using CI/CD pipelines and tools like Jenkins, Docker, Ansible.
Project Tech stack:
JavaScript
HTML
CSS
Python
Django
PostgreSQL
Docker
Jenkins
Ansible
CI
CD
AWS

Languages

English
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