Vitalii – React, Python, Node.js

Founding Engineer at Lemon.io, working part-time as a hands-on engineer embedded with client teams sourced through the platform. Delivered three projects end-to-end:

Fusionmetrics (https://www.fusionmetrics.io), a revenue analytics and attribution tool for Shopify apps.

Currents (https://currents.dev), a platform to debug, troubleshoot, and analyze parallel CI tests in the cloud supporting Cypress and Playwright.

Co AI, an all-in-one platform for creating, sharing, and using generative AI collaboratively.

Fusionmetrics - revenue analytics and attribution for Shopify apps. Worked solo helping the technical founder bring the MVP live, focused on data analysis and building live dashboards for existing clients.

• Built a new data processing pipeline using Python
• Architected a new React.js frontend connected to a FastAPI backend
• Built deployments and CI/CD process for all services
• Redesigned frontend/backend communication by moving data through Parquet files, allowing charts to look more dynamic without losing performance

Currents - debug, troubleshoot, and analyze parallel CI tests in the cloud, supporting Cypress and Playwright. Joined as an individual contributor and the first hire to work with the technical founder.

• Built automatic email reports (daily, weekly, monthly) based on Elasticsearch data while improving Elasticsearch performance and the data structures for other modules; increased user engagement 3 times
• Optimised and extended Stripe integration, including subscriptions plan management, overage fee payments, invoices, and custom plans support, decreasing customer support tickets 3 times
• Built a tests explorer UI component using custom SVG components and visx, widely used across the project
• Constantly improved documentation and code quality by adding unit tests

Co AI - an all-in-one platform for creating, sharing, and using generative AI collaboratively. Brought in to work with a non-technical founder and independently bootstrap and build a solution that could be scaled once validated.

• Built and architected the project from scratch using Next.js, TypeScript, TailwindCSS, and Supabase for database and real-time communication
• Integrated all available AI generative models and built a way to work with AI agents inside the platform
• Implemented chat where multiple users can communicate with each other and AI agents
• Integrated Stripe payments combining subscriptions and token-based usage
• Implemented a complex role management mechanism with public/private channels and spaces.

This product empowers brands with the technology to embrace circular fashion. This allows the brand's customers to put back on sale their past purchases and get paid back within days.

One of the first hires in the Lisbon office. Reported directly to the CEO, owning engineering strategy, delivery, and team building across a distributed European team of ~20 engineers.

> Built and scaled the engineering department from the ground up; hiring manager for backend, frontend, DevOps, and data roles > Led the implementation of a BigQuery-based data warehouse, hiring the first Data Engineer gave every team self-serve access to operational and business data > Drove adoption of AI across product workflows; led a project using AI models for second-hand item digitisation, cutting operational processing time significantly - Established engineering processes, development culture, and technical standards to support rapid scaling across 30+ marketplace integrations > Partnered with Product, Operations, and C-suite to align engineering priorities with enterprise client launches and platform growth

British-Portuguese online luxury fashion retail platform that sells products from over 700 boutiques and brands from around the world. He joined Farfetch to work on a new open-source project - Performance testing as a platform - and led and developed several projects inside the company.

• I joined Farfetch to work on the new open-source project - Performance testing as a platform.

  I lead and develop a few projects inside the company:

  > Performance testing as a service. Which was used inside the company and helped to decrease time spent on execution 3 times and helped to prepare the platform for a few sales seasons.

  > Traffic management tool. Actively participated in designing and building a tool to manage traffic between different data centers with the support of performance metrics.

  > Live visibility. Service to visualize service catalog inside the company (1000 services) their relations and compliance. The service was built in 2 months and had great success in adapting by different teams. The tool helped to decrease the time to resolve incidents by 20%.

  > Bot caching & CDN performance. Built tooling around CDN to have better visibility over bot attacks and monitor CDN performance over years.

Team Lead role at Wise Engineering spanning two projects.

Jobsearcher - collects, indexes, and makes available every job that has ever existed, giving job seekers the power to research all jobs and companies they might be a fit for.

Paddle8 is an online auction house based in New York City selling fine art, including Post-War and Contemporary art, prints & multiples, photography, street art, and collectables. He led a fully distributed team across multiple timezones, working through the full stack from mobile applications to backend implementation.

• Developed search through 200 million jobs
• Built a team of 4 backend and 2 frontend engineers
• Created scalable AWS architecture based on AWS ECS
• Wrote unit, functional, e2e tests
• Was a part of the early startup and helped with early engineering decisions
• Contributed to yearly and quarterly project goals
• Mentored and evangelized best engineering practices about systems design and code quality
• Managed ELK stack to provide observability about all microservices
• Created a Kubernetes cluster and moved all services to it, dramatically improving the deployment process and enabling multiple daily deployments
• Moved legacy PHP and Node.js applications to a Python GraphQL API
• Developed early stages of iPad and iPhone applications
• Redesigned the front-end to make it faster and easier to support, which led to better user engagement