Hello, I'm Andrew Ovsyannikov
Software Architect • Full-Stack Developer • Technical Lead
I specialize in designing project architecture and building scalable, high-performance systems using TypeScript(Node.js, NestJS, Express), Python(FastAPI, Django), and modern front-end frameworks (Vue/Nuxt, React/Next, Angular). I'm also proficient in PostgreSQL, MongoDB, Docker, Nginx, Redis, RabbitMQ, and Kafka. I'm experienced in leading projects, machine learning integration, and performance optimization.
Professional Experience
Site: layer3.press
Skills: JS/TS(Bun, Elysia, Drizzle, React, Remix, Zustand), PostgreSQL, Docker, Kubernetes, AWS, Kafka, Redis, Nostr, LLMs(ChatGPT, Gemini).
Overview:
- Developed layer3.press, a multi-tenant blogging platform combining decentralized publishing via Nostr, subscription-based monetization, AI-powered content workflows, and automated publishing systems.
- Designed and implemented core full-stack architecture, including backend APIs, frontend applications, authentication systems, event-driven services, background processing, and scheduled workflows.
- Built scalable content aggregation, processing, and publishing pipelines supporting automated content creation and distribution.
Nostr Ecosystem:
- Designed and implemented a Nostr-based blogging ecosystem using Nostr protocol specifications (NIPs) and an event-driven architecture for content publishing (notes and articles), direct messages, social features (pins, profile search, comments, reactions), and monetization (article donations via zaps).
- Built authentication systems supporting email OTP and Nostr-based authentication via secret keys or browser extensions.
- Developed services for multi-relay event publishing, Nostr event indexing and caching, profile synchronization, and automated content publishing workflows.
Content Management & Creation:
- Developed a customizable MJML-based email template editor with dynamic content blocks, user metadata, and article data injection.
- Built a Lexical-based editor with custom plugins for images, YouTube embeds, Nostr integration, and paywall functionality, including article preview support.
- Implemented a Markdown-to-HTML conversion pipeline.
Subscriptions & Monetization:
- Implemented subscription and monetization features including Stripe Connect integration, paid blog subscriptions, paywalled content access, and configurable subscription plans.
- Developed guided onboarding flows with gamification, enabling bloggers to configure monetization and publishing settings, featuring a "go-live" mechanism that prevents automated publishing workflows to Nostr until configuration is complete.
- Added publisher membership management.
AI-powered Features:
- Developed AI-powered content processing and generation features, including:
- article summarization;
- content translation;
- image generation;
- generating new articles based on crawled publisher data;
- summarizing and analyzing opposing opinions on the same topic.
- Implemented real-time narrative generation for trending topics.
- Developed AI-powered article re-ranking to surface the most relevant and interesting content.
- Developed automated content processing pipelines for article creation, signing, and publishing using AWS KMS-based secret storage for secure key management.
Infrastructure and Integrations:
- Implemented RSS URL normalization for specific blogging platforms and developed crawling pipelines for automated content ingestion from RSS feeds and websites.
- Built high-load background job processing with SSE notifications for long-running tasks and reactive UI updates.
- Implemented X (Twitter) profile synchronization with Nostr blog.
- Added hCaptcha-protected forms.
Site: EURO ATLANTIC SMART TECHNOLOGY LTD
Skills: JS/TS (NestJS, Prisma), Python (FastAPI, PyTorch, NLTK), PostgreSQL, Docker, Kubernetes, RabbitMQ, Redis, Firebase, Azure (OpenAI, Storage, AI Speech, Custom Question Answering), AWS (S3, Transcribe, EC2), LLMs (Anthropic, ChatGPT, Gemini, Phi-3, Llama), LangChain, Langflow, ChromaDB.
Overview:
- Led development of AI-powered knowledge management and Q&A platforms integrating modern LLMs, cloud AI services, and RAG-based systems.
- Designed and implemented full-stack architecture including scalable backend services, real-time communication, AI workflows, and data processing pipelines.
- Improved AI response quality through RAG optimization, evaluation metrics, and advanced retrieval techniques.
AI Q&A Platform:
- Developed an AI-powered Q&A chat system with REST API and SSE-based streaming responses using modern LLMs and cloud AI services.
- Built knowledge base management workflows with document processing, OCR, audio transcription, and data preprocessing for RAG systems.
- Integrated external knowledge sources and enterprise platforms including LMS Docebo, Google Drive, and AWS services.
RAG & AI Optimization:
- Optimized RAG system accuracy using parameter tuning with Optuna, re-ranking with Cohere, and evaluation using RAGAS metrics.
- Led integration of LangChain and Langflow to improve AI workflow development and orchestration.
Site: UDev
Skills: JS/TS (NestJS, Prisma), Python (FastAPI, Django), Socket.IO, React, PostgreSQL, Docker, Kubernetes, Kafka, MongoDB, GCP.
Overview:
- Modernized existing backend systems by migrating legacy architectures, improving performance, and introducing scalable solutions.
- Developed voice assistant and IoT integrations using NLP-based command processing and smart speaker APIs.
Tumeke Platform:
- Migrated the Tumeke project from Python to NestJS and redesigned the architecture for improved performance and maintainability.
- Developed an algorithm for calculating and visualizing Ergonomic Posture Risk Assessment.
- Optimized raw SQL queries and improved API response times by 30x.
Smart Speaker Integration:
- Developed Yandex Alice skill with authentication APIs to play background music on smart speakers using NLP-based command processing.
Site: Upwork Profile
Skills: Node.js (Express), Python (Flask, Tornado), Vue, React, GraphQL, RabbitMQ, Docker, PostgreSQL.
Overview:
- Developed full-stack solutions for gamified assessment and video surveillance platforms with real-time processing requirements.
- Designed scalable backend architectures, complex business logic, and configuration-driven frontend systems.
- Implemented real-time features including communication, video streaming, and data processing pipelines.
Gamified Assessment Platform Cibirlan:
- Developed a tournament scheduling system.
- Implemented team creation algorithms with role assignment logic.
- Built real-time chat functionality using Socket.IO.
Video Surveillance Platform:
- Implemented WebRTC-based video streaming pipelines for real-time surveillance processing, enabling integration of computer vision algorithms including object tracking, image enhancement, and stream analysis.
- Designed a configuration-driven frontend architecture of an administration panel where UI components, layouts, and behavior were dynamically controlled through backend-provided configurations.
Site: Altermeliora
Skills: TypeScript, Node.js (NestJS), React.js, Python (Django), PostgreSQL, Redis, MongoDB, Docker, GCP.
Overview:
- Developed a full-stack e-commerce and payment platform for selling digital courses and physical products.
- Designed and implemented complex business workflows including product management, checkout processes, payments, invoicing, taxation, and sales analytics.
- Integrated multiple external services for payments, delivery, email communication, and third-party course platforms.
E-commerce & Payment Platform:
- Developed product management features including product forms and category hierarchy builders.
- Implemented invoice generation workflows with payment configuration, discounts, promo codes, and seller tax calculation.
- Built customizable checkout flows with automated registration on third-party services.
- Developed sales reporting and analytics functionality.
External Integrations:
- Integrated delivery services including Shiptor and ChinaDivision.
- Integrated payment providers including Bluesnap, Fondy, PayPal, YooMoney, and Stripe.
- Implemented email delivery workflows using SendGrid.
- Integrated external course-selling platforms.
Additional Features:
- Developed calorie calculation functionality.
- Implemented cross-platform synchronization.
- Built multilingual interfaces.
Site: Upwork Profile
Skills: TypeScript, Node.js (NestJS), Angular, AWS (Amplify, Lambda, DynamoDB, Cognito), RabbitMQ, Docker.
Overview:
- Developed full-stack solutions for logistics, SaaS, and security-oriented platforms.
- Designed scalable cloud architectures with AWS services, authentication systems, asynchronous processing, and flexible business workflows.
- Built configurable applications with automation features, third-party integrations, and AI-powered processing components.
Freight Transportation Platform:
- Developed an administration panel for an MVP freight transportation system.
- Implemented Cognito-based authentication, geocoding, and data visualization using HERE Maps services.
White-label SaaS Platform I-EXP:
- Designed and implemented scalable architecture for white-label licensing with request-based billing.
- Developed a Telegram bot, neural network training data generation tools, image similarity vector search, and authentication workflows.
Website Security Analysis Platform:
- Developed a system for automated website security analysis and assessment.
Site: YLab
Skills: Python (FastAPI, Django/DRF, Flask), SQLAlchemy, TensorFlow, TypeScript, AngularJS, Vue.js, Go, PostgreSQL, Redis, Celery, Docker, MinIO, S3, Scrapy, Selenium, ClickHouse, MS SQL.
Overview:
- Led development teams of up to 10 engineers while designing and implementing full-stack solutions across fintech, B2B, and internal products.
- Collaborated directly with customers to translate business requirements into scalable technical solutions, planned development roadmaps, managed sprint execution, and coordinated feature delivery.
- Mentored and onboarded new developers, enabling rapid project setup and efficient integration into complex codebases.
ECN.Broker (Esplanade MS, onfin.io):
- Led development of a fintech trading platform including an administration panel, user accounts, trader training pages, landing pages, email templates, authentication, and customer-facing interfaces.
- Developed a MetaTrader 4 integration microservice, Telegram bot, referral program, and Forex calculation tools.
- Integrated RBK.money, AccentPay, Interkassa, and SorexPay payment providers.
- Integrated RAMM copy trading, Bpilot contract specifications, IndigoSoft services, Google Charts, Quill WYSIWYG editor, Claws&Horns, and SendGrid email delivery.
- Developed administration panel, user account pages, email templates, category hierarchy management, and bulk product import.
- Integrated ABBYY translation services for automated product localization.
- Developed product price crawling and bulk price import functionality.
Internal Products:
- Developed internal tools including a CSV/XLS reporting aggregator, user testing platform, and OCR processing system.
Site: Aigeo
Skills: Python (Django, SQLAlchemy), TypeScript, AngularJS, OpenLayers 3, PostgreSQL, PostGIS.
Overview:
- Developed geospatial applications and mapping tools for the Yenisei GIS platform.
- Designed full-stack GIS solutions combining interactive map interfaces with spatial data processing pipelines.
- Built medical GIS features and geospatial data normalization tools to improve the accuracy and quality of spatial analysis.
Yenisei GIS Platform:
- Developed geospatial applications and interactive mapping tools using OpenLayers 3.
- Implemented backend services for processing and managing spatial data with Python, PostgreSQL, and PostGIS.
- Developed medical GIS functionality for visualization and analysis of healthcare-related geospatial data.
Geospatial Data Processing:
- Implemented Aigeo References, a comprehensive geospatial reference management system.
- Developed geospatial data normalization tools for addresses, coordinates, and administrative locations to improve the accuracy of spatial matching and mapping algorithms.
Degree
- Artificial intelligence - Master of Computer Science (MCS) - 2018 - SibSAU.
- Software engineering - Bachelor of Computer Science (BCompSc) - 2016 - SibSAU.
Personal Projects
Beyond my commercial experience, I continuously build personal projects to experiment with new technologies, explore architectural ideas, and develop production-quality systems from scratch.
Visit dev.drewdru.com to explore interactive demos and detailed project pages. If you'd like to dive into the implementation details, my GitHub contains the source code for many of these projects.
Featured Project
Site: ManeTalk
Skills: NestJS, Vue.js, Nuxt, Electron, RabbitMQ, Kafka, Docker, Godot, PostgreSQL, MinIO.
Overview: Developed the ManeTalk website with SSO authentication and a microservices-based backend for game modules. Designed scalable REST and event-driven APIs for managing profile data, character textures, inventories, and real-time chat integrated with the Godot Engine. Implemented advanced anti-abuse systems including per-endpoint rate limiting, gibberish and Detoxify message classification, and multi-account spam and flood detection using Longest Common Subsequence analysis. Built a Telegram bot for administration and moderation, along with a desktop game launcher featuring an integrated anti-cheat system.