Alexey Lunacharsky
Verified Expert in Engineering
Systems Engineering Developer
Tallinn, Estonia
Toptal member since December 17, 2014
Alex is a technology leader with 16+ years of experience, including 10+ years as a CTO, tech lead, and engineering manager. He co-founded Refty, a UAE real estate analytics platform, building the product and a 5-person team and scaling to 1 billion monthly requests while reducing query latency from 8s to 0.4s. He spent 5.5 years at HubSpot working on big data, ETL, and reporting APIs. Alex uses Node.js, TypeScript, Python, and Rust, and holds a First Class Honours MA in Statistics from UCD.
Portfolio
Experience
- Systems Engineering - 15 years
- Team Leadership - 7 years
- ETL - 7 years
- TypeScript - 6 years
- Python - 4 years
- BigQuery - 4 years
- DevOps - 3 years
- AI Agents - 1 year
Preferred Environment
TypeScript, Python, Java, Rust, Zed, Claude Code
The most amazing...
...things I've built are a web scraping system, ETL for analytics, and a web UI for a company that grew to $1 million in cumulative revenue over two years.
Work Experience
Co-founder & CTO
Refty
- Architected a scalable parser with a worker pool pattern processing over 1 billion monthly requests from over five data sources, improving query speed 20×, from 8 seconds to under 0.4 seconds.
- Launched a real estate intelligence platform in 12 weeks with a freemium model supporting B2C and B2B segments.
- Delivered $50,000-$72,000 annual savings through self-hosted CI/CD (88% savings), database pooling, self-hosted Kubernetes, and CronJob optimization (90% reduction).
- Built an AI-powered photo classification and email marketing pipeline, achieving 95% automation in lead qualification, reducing report generation from two hours to 30 seconds.
- Launched a lead-processing system for cold outreach across a WhatsApp account farm, analyzing conversations to recommend next steps.
Senior Software Engineer
HubSpot
- Designed and implemented an ETL infrastructure ingesting 4TB of event data, enabling real-time reporting capabilities.
- Created and enriched internal APIs consumed by sibling teams, improving cross-team data accessibility and removing duplicate pipelines.
- Built monitoring, tracking, availability, and responsiveness metrics, enforcing SLA compliance across reporting endpoints.
- Reduced operational costs through infrastructure improvements and resource optimization across data pipelines.
- Conducted 50+ technical interviews and mentored new team members, accelerating time to productivity.
Senior Developer/Manager
Yahoo!
- Led client-side engineering for a video and ad distribution platform serving millions of daily video and ad views across hundreds of publisher sites.
- Managed weekly feature releases, maintaining a predictable shipping cadence across publisher integrations.
- Introduced continuous build, monitoring, and safeguards against video-player failures and downtime that caused direct revenue loss.
- Led cross-platform performance optimization, stabilizing playback across devices and browsers.
- Owned integrations with third-party services and advertising partners across the distribution network.
Tech Lead
Argomedia
- Developed a widget library for interactive ad units, including on-page interactions, mini-games, maps, and an embedded video player.
- Implemented IAB web advertising standards (VAST, VMAP, and VPAID) across the ad server's creative delivery pipeline.
- Built a cross-browser video player with Flash and HTML5 fallback, supporting custom extensions and third-party APIs (JW, Flowplayer, and Brightcove).
- Implemented custom IoC/DI libraries in ActionScript 3 and JavaScript, cutting footprint and simplifying application design.
- Supported the creative team by building reusable UI components for ad production.
CTO
Studio DVA
- Shipped a multiplayer life simulator for VK in eight months, reaching 150,000+ registered users and 100-200 concurrent players at peak.
- Designed the system architecture and implemented server-side web services, tools, and libraries in Java with MySQL.
- Designed server and client sides of a Worms-style online game, implementing physics and a rendering engine.
- Handled deployment on dedicated Debian Linux servers and owned production monitoring.
- Built tooling for UI designers, including a visual blast constructor bound to different weapon types.
Experience
Open Options Pricer
ChatFleet — Virtual Office Run by AI Employees
The focus throughout was turning impressive demos into something dependable enough to actually run real work day to day.
Real Estate Analytics Platform (Dubai Market)
https://refty.ai/I owned the technical direction, hired and led the team, and took the platform from an early-stage concept to a working product, generating $1 million in cumulative revenue over two years—in a market I had to learn from scratch and under real-time pressure.
Education
Master of Arts in Statistics
University College Dublin - Dublin, Ireland
Master's Degree in Mathematics and Applied Programming
Dostoevsky Omsk State University - Omsk, Russia
Skills
Libraries/APIs
Node.js, React, REST APIs, Apache HttpClient, jQuery, Joda-Time, Interactive Brokers API, Claude API, RxJava, Puppeteer, OpenAI API, Nightwatch.js, Video Multiple Ad Playlists (VMAP)
Tools
Flash, JVisualVM, SBT, Git, GitLab, GitHub, IntelliJ IDEA, json4s, BigQuery, Claude, Claude Code, Gradle, JRebel, Adobe Scout, Karma, Jenkins, Zed, Adobe Flash, JW Player
Languages
Java, AS3, JavaScript, TypeScript, Python, Snowflake, Less, CSS, HTML5, MXML, Scala, SQL, Bash, Clojure, Rust, ActionScript 3
Frameworks
AngularJS, Netty, RobotLegs, Express.js, Spring, Next.js
Paradigms
ETL, DevOps, Functional Programming, Agile Software Development, Concurrent Programming, Model Context Protocol (MCP), Event-driven Architecture, Scrum
Platforms
JVM, Kubernetes, Google Cloud Platform (GCP), OS X, Google Chrome, Visual Studio Code (VS Code), Docker, Amazon Web Services (AWS), Linux
Storage
PostgreSQL, MongoDB, Redis, MySQL, Amazon S3 (AWS S3), EdgeCast, Apache Hive
Other
Software Development, Systems Engineering, APIs, Team Leadership, Artificial Intelligence (AI), Code Review, Generative Artificial Intelligence (GenAI), Full-stack, Technical Leadership, Software Architecture, Data Scraping, Web Scraping, AI Tools, API Integration, AI Integration, Back-end, Algorithmic Trading, Full-stack Development, Data Analytics, Data Modeling, ETL Pipelines, Software Engineering, Cookies & Tracking, Apache Commons, Adobe Flash Builder, Machine Learning, AI Agents, Trading, Agentic AI, Retrieval-augmented Generation (RAG), RAG Systems, OpenAI, FastAPI, TradingView, AI Automation, Backtesting Trading Strategies, Cursor AI, Large Language Models (LLMs), Workflow Automation, Real Estate, Workflow Automation & System Integration, Data Science, Pricing, Advertising Technology (Adtech), Financial Modeling, Core Web Vitals, WebSockets, Applied Mathematics, BullMQ, Monitoring, Flash/AS3, Akamai, Content Delivery Networks (CDN), Statistical Methods, Design of Experiments (DOE), Statistical Modeling, Neural Networks, GARCH Model, Monte Carlo Simulations, Finance, WebAssembly (Wasm), Orchestration, Prompt Engineering, Agent skills, SaaS, Database Analytics, VAST, VPAID, Front-end, Video Streaming, Cross-browser Compatibility, Web Services, Game Development, Physics Engines, Programmatic Advertising
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