👋 Hi there! I’m a results-driven Senior Full Stack Developer with 8+ years of experience building scalable cloud-based applications, APIs, dashboards, and production-grade business systems. I help startups, growing businesses, and enterprise teams turn raw data and business ideas into reliable, scalable, and high-performance solutions. Whether you need a *data pipeline, cloud data warehouse, analytics dashboard, backend API, web application, desktop app, or full business automation system*, I can take ownership from planning to deployment. 🌟 What I Can Help You With 🔹 Cloud Data Platforms I work with modern cloud platforms including AWS, GCP, and Azure to build secure, cost-efficient, and production-ready data systems using services such as S3, Redshift, Lambda, Glue, Athena, BigQuery, Dataflow, Azure Data Factory, Synapse, and Blob Storage. 🔹 Full Stack Web & Desktop Applications I build modern, scalable applications using JavaScript, TypeScript, Angular, Node.js, NestJS, ElectronJS, .NET Core, MongoDB, PostgreSQL, and REST APIs*. From MVPs to full-scale enterprise systems, I focus on clean architecture, performance, and long-term maintainability. 🔹 Data Engineering & ETL/ELT Pipelines I design and build scalable data pipelines for ingestion, transformation, validation, and reporting using tools like Python, SQL, Apache Airflow, Spark, Kafka, dbt, Pandas, Snowflake, BigQuery, Redshift, and AWS Glue. 🔹 Dashboards, Reporting & Analytics I create business-focused dashboards and reporting systems using Power BI, Tableau, Superset, SQL, and cloud data warehouses, helping teams make faster and better decisions. 🔹 Automation & Workflow Optimization I automate manual business processes, reporting workflows, data syncs, API integrations, and backend operations to save time, reduce errors, and improve efficiency. 🔧 Tech Stack Languages: Python, SQL, JavaScript, TypeScript, Bash Frontend: Angular, HTML, CSS, responsive UI development Backend:Node.js, NestJS, .NET Core, REST APIs Desktop Apps: ElectronJS Databases: PostgreSQL, MySQL, MongoDB, SQL Server, Snowflake, BigQuery, Redshift Data Tools: Airflow, Spark, Kafka, dbt, Pandas, NumPy Cloud:AWS, GCP, Azure AWS Services: S3, Lambda, Glue, Redshift, Athena, ECS DevOps: Docker, Kubernetes, GitHub Actions, Terraform, CI/CD Visualization: Power BI, Tableau, Superset 💼 Why Work With Me? ✅ End-to-End Ownership — I can handle everything from data architecture and backend development to deployment and reporting. ✅ Production-Ready Delivery — I build clean, reliable, documented, and scalable solutions. ✅ Business-Focused Approach — I don’t just write code; I build systems that solve real business problems. ✅ Strong Communication— I keep projects clear, organized, and easy to understand. ✅ Fast & Reliable Execution — I focus on quality delivery with practical timelines and clean results. 🚀 Whether you need a data engineering solution, cloud pipeline, full stack application, business dashboard, API integration, or automation system, I’m ready to help you build it properly. 📩 Let’s connect and discuss how I can help bring your project to life.

22+ years designing enterprise systems built for reliability, performance, and long-term maintainability. I currently serve as Head of Technology for OursTube, a video streaming platform, alongside consulting engagements for startups and growing businesses. I've shipped 50+ platforms — a government compliance system for 5,000+ Pakistan Railways employees (World Bank-audited), an AI module that cut manual data entry by 85%, FinTech backends handling payments across UK, UAE and Europe, and a YouTube-style video platform with WebRTC real-time chat serving thousands of concurrent users. If you need someone to write a feature and disappear, I'm not the right fit. If you need someone who thinks about schema design, security, query performance, and what happens at 3x your current load — that's exactly what I do. ━━ WHAT I BUILD WELL ━━ ► FinTech & Payment Systems Built complete payment ecosystems including Stripe Connect onboarding, subscriptions, creator payouts, webhook orchestration, payment abstraction layers, and multi-provider payment integrations (Stripe, Wise, Payoneer, JazzCash, EasyPaisa). ► Backend Architecture (Node.js / Laravel / NestJS) Designed scalable RESTful and GraphQL APIs with optimized PostgreSQL queries, Redis caching, and clean service boundaries for high-performance enterprise applications ► PostgreSQL at Scale Schema design, migration strategies, index optimisation. I reduced a government system's query time from 15 seconds to 200ms. Connection pooling, partitioning, full audit logging for compliance. ► AI / OpenAI API Integration Production AI systems using OpenAI GPT-4/4o with OCR, intelligent document processing, provider-agnostic architecture, prompt versioning, structured outputs, and enterprise workflow automation. ► Security & Compliance JWT with refresh rotation, RBAC, OAuth 2.0, audit trails. Passed World Bank security audit for a public-sector system. I treat security as architecture, not a checkbox. ► Amazon SP-API / Shopify / E-commerce Japanese marketplace integration, multi-vendor fulfilment platforms, rate limit management, exponential backoff. Real resilience patterns, not optimistic code. ► WordPress & WooCommerce (Custom & Complex) Multi-vendor WooCommerce platforms with custom commission logic, AJAX cart systems, ACF Pro integrations, and vendor dashboards. WP Rocket + Cloudflare configuration. Custom PHP plugins, payment gateway integration (Stripe, PayPal, JazzCash), and performance optimization for high-traffic stores. I debug codebases I didn't write — fast. ━━ PAST ENGAGEMENTS ━━ • Pakistan Railways (2021–2023) — Audit & Fuel Management systems for 5,000+ staff. World Bank compliance. Query optimisation: 15s → 200ms. • YetiScanner AI (2024) — OpenAI GPT-4 document processing for YetiForce CRM (Netherlands). 85% reduction in manual invoice entry. • Global Connect ERP (Bahrain, 2024–2025) — Oracle monolith → PostgreSQL microservices. 3× performance improvement. • Ourstube Media (2025–Present, Current) — Head of Technology for a YouTube-style platform: Node.js microservices, WebRTC, custom AdTech, 4-provider payment abstraction. 60% faster video processing via CDN. • Thread Production ERP (2024) — Multi-tenant Laravel 11 system for textile manufacturing. Complex RBAC across multiple facilities. ━━ STACK ━━ Node.js · TypeScript · NestJS · Express Laravel (5–11) · PHP PostgreSQL · MySQL · MongoDB · Redis · Oracle AWS (EC2, S3, RDS, Lambda, CloudWatch), Docker, Redis, Grafana, GitHub Actions OpenAI API · WebRTC · WebSockets Stripe · Twilio Voice · Twilio Functions · SendGrid · Shopify API · Amazon SP-API · WooCommerce ━━ HOW I WORK ━━ I take a small number of engagements at a time so I can give each one proper attention. I communicate daily, push working code early, and flag risks before they become problems. Timezone: PKT (UTC+5) — available for UK, UAE and European business hours with overlap. Whether you need it built, or need an architect to validate the plan and pressure-test the decisions before you build — that's work I do. If your project involves backend architecture, payment systems, AI integration, database performance, ERP/systems integration, or taking a messy codebase and making it production-ready, send me a message with what you're building. I'll tell you honestly if I'm the right person for it.

My longest client has been with my team for 7 years and over $1M of continuous development. Another project started as a $7K MVP and grew into a $70K product — because it was architected to survive success from day one. I'm Sergei — founder and CTO of a senior engineering team that designs and builds AI-powered SaaS platforms: multi-tenant architecture, AI agents, and the unglamorous production infrastructure that keeps them alive under real users. Here's the uncomfortable truth about how founders usually find me: I'm the second team they hire. Recently a client brought us a "finished" AI SaaS platform before launch. Our architecture audit found 4 critical blockers and 11 high-risk issues the previous team had left behind — each one cheaper to fix on paper than in production. Cheap code isn't cheap. It's a mortgage you didn't know you signed. WHAT I ACTUALLY DO 1) AI SaaS Product Engineering Multi-tenant platforms with AI agents built in — not bolted on. My rule: LLMs go where they create value users pay for; deterministic, testable code goes everywhere else. That discipline is the difference between an AI demo and an AI product. 2) Architecture Audits & Production Rescues A fixed-price, fixed-scope review of your codebase before launch or investment: architecture assessment, risk register, production-readiness score, and a prioritized roadmap. You own the report whether or not we continue together. This is the single highest-ROI engagement I offer — every hour of audit saves 10–20 hours of rework. 3) Long-Term Product Development (T&M) For founders who want a technical team that thinks in years, not sprints. Time-and-materials with full transparency: you see who works on what, at which rate, every week. Fixed-price rewards vendors for cutting corners you won't see for months; T&M rewards us for exactly one thing — keeping you happy enough to continue. Our 7-year client relationship exists because of this model, not despite it. HOW THE TEAM WORKS You'll be working with me directly on architecture and key decisions — and with my senior engineers on delivery, at rates below mine, with full visibility into who does what. You get founder-level attention with team-level throughput. I personally review the architecture of everything we ship. I build for non-technical founders deliberately. You're an expert in your domain — you shouldn't need to learn what a message queue is to make good decisions. Every technical choice comes to you as a business decision: what it costs, what it risks, what it unlocks. STACK (the boring part) Python, Node.js, React/Next.js, PostgreSQL, Redis, AWS, Docker, CI/CD. AI: Claude & OpenAI APIs, RAG pipelines, multi-agent orchestration, evaluation and guardrails for production LLM systems. NEXT STEP If you're building an AI SaaS product — or rescuing one — message me with a short description of where you are. If there's a fit, we'll start with a 15-minute call, and usually from there with an Architecture Audit: fixed price, fixed timeline, a report you keep either way.

Three things I do best: voice agents that sound human, multi-agent orchestration that actually ships, and RAG systems that hold up in production. Voice agents. People on the other end of the call don't realize they're talking to an AI. That takes a lot of small things working together: VAD endpointing so the agent starts responding before the caller finishes, barge-in so it stops when interrupted, filler words and breathing pauses between sentences, dynamic speaking rate that slows down for complex info, sentiment-driven tone shifts, voice cloning. Sub-300ms latency. Self-hosted models alongside cloud providers. SIP telephony for outbound calls, plus inbound with intent routing and human handoff. Agent orchestration. Built a system with five specialist agents (voice, browser, RAG, MCP tools, scheduler) that coordinate through dependency DAGs and run in parallel. The agents work through real tools: browser automation via Chrome DevTools Protocol, MCP servers managing Google Calendar, Gmail, GitHub, PostgreSQL, Slack. Per-room credential isolation. Human-in-the-loop approval gates for sensitive operations like calls and emails. AI that takes real actions, not just answers questions. Production RAG. I've shipped: Legal RAG (FlawFinder.ai) indexing US police departments, zero-hallucination citations, paying subscribers Scientific document RAG with hybrid search, multi-language support, figure extraction via vision models GraphRAG with 40% better retrieval vs vector search alone I also help teams whose RAG works in demos but struggles with real data. Usually it's chunking strategy, missing evaluation, or grounding gaps. I audit the pipeline and rebuild the parts that need it. Beyond the AI layer, I build the infrastructure that keeps systems running when real users show up: Kubernetes, CI/CD, monitoring, evaluation harnesses. Most recently Infrastructure Lead at an AI startup where I built the full platform from scratch. Day to day: Python (FastAPI, Django), LangChain/LangGraph, PostgreSQL, pgvector, Redis, Kubernetes, Docker, Terraform, AWS. Frontend when needed (React/TypeScript). 15+ years in software, last 3 on LLM applications. Based in Madrid (GMT+2), flexible for EST overlap. Available now, async-first, same-day responses.

𝗣𝘆𝘁𝗵𝗼𝗻 𝗙𝘂𝗹𝗹 𝗦𝘁𝗮𝗰𝗸 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿 with 𝟰+ years of experience building scalable SaaS platforms, AI-powered applications, backend systems, and modern web products. I help startups and businesses build, improve, and scale software using 𝗣𝘆𝘁𝗵𝗼𝗻, 𝗙𝗮𝘀𝘁𝗔𝗣𝗜, 𝗗𝗷𝗮𝗻𝗴𝗼, 𝗥𝗲𝗮𝗰𝘁, 𝗡𝗲𝘅𝘁.𝗷𝘀, and modern API-driven architecture. My core expertise is in building clean, scalable backend systems while also handling full-stack product development for SaaS, AI integrations, dashboards, automation tools, and API-heavy platforms. ⚡ 𝗪𝗵𝗮𝘁 𝗜 𝗖𝗮𝗻 𝗛𝗲𝗹𝗽 𝗬𝗼𝘂 𝗪𝗶𝘁𝗵: • Python Backend Development (FastAPI, Django, Flask) • Full Stack SaaS Development • REST API Development & Third-Party Integrations • AI Integrations (OpenAI, Claude, Gemini, LLM Workflows) • React.js & Next.js Applications • Stripe Payment & Subscription Systems • Database Design (PostgreSQL, MySQL, Redis) • Automation Workflows (Selenium, Playwright) • Web Scraping & Data Extraction • AWS Deployment, Docker & Cloud Infrastructure • Existing Codebase Refactoring & Performance Optimization 🚀 𝗥𝗲𝗰𝗲𝗻𝘁 𝗪𝗼𝗿𝗸: • Built AI SaaS MVPs using FastAPI, React, and OpenAI • Developed scalable API systems handling thousands of requests • Built Stripe payment and subscription workflows • Created real-time dashboards and notification systems • Refactored and scaled production SaaS codebases • Built automation pipelines and browser workflows • Integrated complex third-party APIs for business systems 🛠️ 𝗧𝗲𝗰𝗵 𝗦𝘁𝗮𝗰𝗸: 𝗣𝘆𝘁𝗵𝗼𝗻 • 𝗙𝗮𝘀𝘁𝗔𝗣𝗜 • 𝗗𝗷𝗮𝗻𝗴𝗼 • 𝗥𝗲𝗮𝗰𝘁 • 𝗡𝗲𝘅𝘁.𝗷𝘀 • 𝗢𝗽𝗲𝗻𝗔𝗜 • 𝗣𝗼𝘀𝘁𝗴𝗿𝗲𝗦𝗤𝗟 • 𝗥𝗲𝗱𝗶𝘀 • 𝗦𝘁𝗿𝗶𝗽𝗲 • 𝗗𝗼𝗰𝗸𝗲𝗿 • 𝗔𝗪𝗦 • 𝗔𝗣𝗜𝘀 • 𝗔𝘂𝘁𝗼𝗺𝗮𝘁𝗶𝗼𝗻 • 𝗣𝗹𝗮𝘆𝘄𝗿𝗶𝗴𝗵𝘁 Whether you need to build an MVP, integrate AI into your product, develop scalable APIs, automate workflows, or improve an existing SaaS platform — I can help you ship reliable, production-ready software. ✅ Long-term collaboration ✅ Fast communication ✅ Clean, maintainable code ✅ Strong problem-solving mindset

Python Django full stack developer specializing in SaaS MVPs and fintech platforms - 14 production-ready SaaS MVPs delivered in 4 to 6 weeks across fintech, expense management, and AI-powered web applications. I build scalable web applications that go from idea to working product fast: Django REST databases, and OpenAI API integrations. My focus is on clean architecture that's easy to maintain and extend - not overengineered, not held together with duct tape. My core work covers full stack SaaS development from MVP to production, multi-tenant SaaS architecture, Django and FastAPI backends with role-based access and authentication, subscription and payment integration, React and Node.js frontends, AI integrations using OpenAI API and Google Document AI, and cloud infrastructure on AWS with Docker. How I work: I start by mapping exact requirements and proposing a tech stack that fits your timeline and budget. I move fast, communicate clearly, and deliver working software - not just code. Every project includes documentation and handover so your team can take ownership after launch. Recent work: Built an AI-powered check scanning feature for Spendbase, a B2B expense management SaaS platform based in Delaware. Using Python and Google Document AI, we automated data extraction from paper checks and integrated it into their existing expense workflow - delivered on a tight deadline with full documentation and zero disruption to the live platform. If you need a production-ready SaaS MVP, a Django backend with AI integration, or a reliable Python full stack partner for the long term, let's talk.

I build production backends for SaaS platforms and AI-powered products, systems where clean architecture, reliability, and real engineering decisions actually matter. Current work includes: - Backend infrastructure for a large-scale AI app-builder platform (TypeScript, Python, Next.js, AWS ECS/Fargate, multi-agent orchestration across 10+ services) - FinTech portfolio investment LLM for wealth managers (Go, PostgreSQL, REST APIs) - Real-time EV charging and IoT systems (Go, OCPP, MQTT, AWS IoT Core, Kinesis) What I can help with: - Backend APIs and service design — TypeScript/Node, Python/FastAPI, Go - AWS infrastructure — ECS, RDS, S3, Lambda, Terraform - AI product backends — LLM integration, agentic workflows, multi-service coordination - Event-driven and real-time messaging systems - SaaS MVP backends and production reliability improvements - PostgreSQL, Redis, DynamoDB I work best on projects that need someone who can own the backend end-to-end, from architecture to deployment. If your project fits, send me a message.

I help companies ship production software that scales, performs, and sells. Tech-lead by day, code artisan by night, I pair deep Python expertise with modern JavaScript, cloud DevOps and hands-on AI integration to turn ideas into revenue-generating products. ⸻ 🔑 Core Strengths • Python Back-End – Django, Flask, FastAPI, Celery, async I/O, REST & GraphQL • Front-End – React / Next.js (SSR & SSG), Vue, Mithril, Tailwind, TypeScript • AI / LLMs – OpenAI, Google Gemini, Anthropic Claude → translation, content generation, semantic search, RAG, agents & automations • DevOps – Kubernetes, Docker, Terraform, GitHub Actions, GitLab CI, Jenkins • Cloud – AWS (ECS, EKS, RDS, S3, CloudFront), GCP, DigitalOcean • Data & Viz – PostgreSQL, Redis, Pandas, Plotly Dash, Streamlit • Quality First – TDD/BDD, pytest, Playwright, Pact, Sentry, 90 %+ coverage targets ⸻ 📈 Results I Typically Deliver • 4× inbound leads by architecting a DRF/Next.js platform with AI-generated SEO that hit 100 % Core Web Vitals in six weeks. • -48 % API latency on a genomics Dash app via async workers & smart caching. • Telegram trading Crypto bot broadcasting to 50 k users/day with 99.9 % uptime (Docker Swarm + AWS). • Mentored dev teams, instituted CI/CD & IaC pipelines, and raised test coverage from 55 → 95 % on multiple projects. ⸻ 🚀 How I Can Help You 1. End-to-End Product Delivery – turn a concept or requirements document into a secure, scalable, production-ready application (web, mobile, or SaaS). 2. AI Enablement – chat, summarisation, translation or data-insight features powered by OpenAI/Google Gemini/Claude. 3. Performance & Reliability Upgrades – profiling, caching, micro-services, observability. 4. DevOps Overhaul – Docker-first workflows, Kubernetes clusters, zero-downtime CI/CD. 5. Technical Leadership – architecture reviews, team mentoring, roadmap planning. ⸻ I continuously invest in professional development—tracking emerging technologies, completing advanced courses, and engaging with leading engineering communities. This commitment keeps my toolbox modern and ensures every solution I architect leverages battle-tested best practices. Passion for elegant, maintainable code guides every decision I make. 💬 Need a partner who thinks in user stories, speaks in pull requests, and backs decisions with metrics? Click “Invite to Job” and let’s build something exceptional.

Hi, I'm Oleksiy. I am a senior engineer with 9 years of experience. I like to write clean code, and although I have a lot of experience, I spend time every day learning new languages, frameworks, optimizing workflows, and so on. One of my biggest strengths is solving problems. My task is to realize YOUR ideas and create an amazing product. I specialize in architecting high-scale e-commerce ecosystems and complex microservices. With a focus on the TALL stack and AWS, I transform business requirements into scalable, production-ready web applications. Technical expertise: Core Frameworks: ✔️ PHP 8.x, Certified Laravel Expert; ✔️ TALL Stack (Tailwind, Alpine, Livewire); ✔️ Filament PHP (Admin & Panels). AI & Intelligent Systems: ✔️ LLM Integration (OpenAI, Claude, OpenRouter); ✔️ Vector Databases; ✔️ AI-driven automation. Cloud Architecture (AWS & GCP): ✔️ AWS: EC2, Fargate, Serverless (Lambda), SQS/SNS, EventBridge, S3; ✔️ GCP: Cloud Run, BigQuery, Load Balancing. Database & High-Performance Search: ✔️ SQL/NoSQL: PostgreSQL, MySQL, MariaDB, MongoDB, SingleStore; ✔️ Caching & Discovery: Redis (Pub/Sub), ElasticSearch, Memcache. DevOps & Infrastructure: ✔️ Docker (Expert); ✔️ Laravel Forge/Vapor/Envoyer; ✔️ CI/CD (GitHub Actions, Jenkins). Core Competencies: ✔️ AI Orchestration & LLM Integration. Engineering intelligent systems using OpenAI (GPT-4o), Claude, and AWS SageMaker for automated content generation, sentiment analysis, and conversational AI (Telegram/Slack/Discord). ✔️ High-Scale Cloud Architecture. Designing and deploying resilient, serverless infrastructures on AWS Fargate and Google Cloud Run. Expert in auto-scaling, load balancing, and handling high-traffic surges for rapidly growing startups. ✔️ Enterprise E-Commerce & FinTech. - Payment Systems: Seamless integration of Stripe, PayPal, Braintree, and specialized providers like LiqPay. - ERP/CRM Sync: Deep-level integration with HubSpot, E-Conomic, and Uniconta. ✔️ Advanced Microservices & Backend Engineering. Architecting distributed systems and microservices using Laravel. Expert in background data processing via complex queue management (SQS/Redis) and scheduled task orchestration. ✔️ Full-Cycle Platform Development End-to-end engineering of bespoke CRMs, multi-vendor marketplaces, and high-performance SaaS applications using the TALL Stack and Filament PHP. Feel free to contact me about projects of any complexity. I guarantee that the work will be done efficiently and on time.

Hi, I'm Aldo — a Senior Backend Engineer specializing in high-scale, cloud-native systems built with Golang, TypeScript, and Node.js. Over the past 10+ years, I've engineered backend platforms serving millions of users — from telecom infrastructure at Telkom Indonesia, to insurance eCommerce at AIA Singapore, to commodity trading systems handling 30,000+ daily transactions. I don't just write code; I take ownership of architecture, lead teams, and deliver production-grade systems end-to-end. 🚀 What I Can Help You With 🔧 Backend & API Development High-performance RESTful & gRPC APIs Node.js, TypeScript, Golang Clean Architecture, SOLID, CQRS Microservices & distributed systems System design for high traffic and peak loads ☁️ Cloud & DevOps AWS, Google Cloud, Azure Kubernetes (AKS, EKS), Docker CI/CD with Azure DevOps, GitHub Actions, Jenkins Serverless (Lambda, Cloud Run) Infrastructure automation & deployment pipelines 📡 Event-Driven Architecture Kafka-based systems RabbitMQ, Azure Service Bus, Pub/Sub Asynchronous processing & message queues Scalable service-to-service communication (gRPC, Protobuf) 🗄 Databases & Performance MySQL, PostgreSQL, MongoDB, DynamoDB, CosmosDB Redis & Elasticsearch Query optimization & performance tuning High availability & data consistency strategies 📊 Monitoring & Reliability Grafana, Kibana, Cloud Monitoring Logging, alerting, and APM Production issue diagnosis & optimization 🏆 Highlights Built and scaled systems supporting millions of users Led backend architecture for enterprise & startup products Improved deployment speed by up to 90% via CI/CD automation Boosted operational efficiency by 40–80% through automation Strong communicator — comfortable working directly with founders, product teams, and stakeholders I care deeply about code quality, scalability, and long-term maintainability. If you need a backend engineer who can step in, understand your system fast, and build for scale and longevity — let's talk.