Hi 👋,, 14000+ expert experience hours & 15+ years commercial experience overall. High performing Upwork’s awards winning expert with eager to innovate by taking responsibility for the informed decisions. Have worked on dozens of complex solutions for such companies as Microsoft, Technicolor, Solvusoft and many others. Open Source software building, re-branding, and customisation; WebRTC, ZoomSDK integration; Cross-platform Windows, macOS, Unix, iOS, Android solutions; CI/CD with Jenkins, Appveyor, Travis, Circle; Installers; UWP Windows 10 Store development; Certified medical EHR and EMR systems development; xTerm, WinPTY, ConPTY terminal emulators; Blockchain wallets, apps and core development; Games development with Unity and custom engines; ● 6900+ worked hours and 70+ projects completed PERSONALLY only at Upwork ● 2020 and 2018 years - awarded with "The Best Top Rated Freelancer Award in India (Web, Mobile, Software Category) at Upwork." ● Helped 100+ businesses to reach their goals in time ● Microsoft Certified Professional (MCP, 70-483: Programming in C#) I'm providing: - Projects consulting, estimation, application architecture design, and implementation ways foresees. - Code quality and performance review. Team leading and mentoring. - Proactive project management and technical leading to meet success criteria in the most efficient ways. - Tackling sophisticated technical issues (performance optimisation, memory leaking, execution freezing). - Research and technical solution design. - Software development, bug fixing, features implementation. I'm experienced in the code development, software architecture design and projects management. I have worked on a wide range of desktop applications for Windows, OS X, and Linux. Participated in the massive commercial projects development with a team of up to 100 developers, developed numerous apps for desktop and mobile according to the clients' requirements. Therefore I'm capable to work in a group or build software myself from the ground. I prefer to keep work quality in the first place. Had a lot experience in cross-platform desktop development for Windows, OS X, and Linux using C++ / Qt / QML, mobile development for iOS, Android, and Windows Phone. I can create software solutions to support major operating systems from the single code base, develop installers and provide documentation. Technologies stacks: C++, STL, Qt, QML, WinAPI, MFC, ATL React, Redux, JavaScript, TypeScript Unity, Rewired, C#, PlayFab C#, Xamarin.Forms, .NET Framework, .NET Core, Entity Framework Core, WPF, UWP Universal Windows Platform, Windows 10 Objective-C, Cocoa, XCode, iOS Development, Cocos2d, Cocos2d-x NSIS, Advanced Installer, Installers development OOD, application architecture design Kinect development, Microsoft Kinect SDK, PrimeSensor Kinect SDK CMake, Appveyor, Travis CI, CircleCI, Jenkins React Native, ClojureScript, Reagent, Lein, Node.js, React, JavaScript At StackOverflow community rated in TOP %5 for Qt skill and TOP %20 for C++ and QML skills. Kindly message me to get more details about my relevant experience or provide info about your needs! Always open and capable of learning quickly new frameworks and technologies used in your projects!

I am a software craftsman specialized in building distributed infrastructure scalable for processing large volumes of data at high speed. I build flexible systems by composing modular tools that can adapt changes faster. I have been passionately leveraging my skills and delivering software solutions for last 15+ years in different industries. I envision about the end goal of having maximum positive impact for my efforts. I enjoy sharing my knowledge and experience with others.

🚀 Ex-Meta / Yahoo | AI Full-Stack Engineer | GenAI, LLM, SaaS, APIs I build end-to-end AI products — from LLM-powered features to scalable full-stack systems. With 10+ years at Meta, Yahoo, and startups, I’ve shipped production systems used by millions and designed platforms that scale reliably. I focus on delivering real, usable AI applications — not just demos. ✅ What I Can Help You Build: • GenAI Applications: GPT / Claude integrations, AI copilots, workflows, prompt engineering • RAG Systems: chat over documents, knowledge bases, retrieval pipelines • Full-Stack AI Apps: frontend + backend + APIs + AI integration • AI Agents: tool-using agents, automation workflows • Backend Systems: scalable APIs, microservices, cloud architecture • AI SaaS: MVP → production-ready systems 💼 Experience Highlights: • Meta — built large-scale production systems • Yahoo — personalization systems serving billions of requests/day • Indeed / Workday — scalable backend and cloud platforms • Tech Lead — owned architecture and built systems end-to-end • Real-time systems processing TBs/day (Kafka, distributed systems) 📊 What You Get: • End-to-end builder (AI + full-stack + product) • Production-ready systems, not fragile prototypes • Scalable architecture from day one • Fast execution and clear communication 🔧 Tech Stack: AI: GPT-4/5, Claude, RAG, AI agents, prompt engineering Frontend: React, Next.js, TypeScript Backend: Python (FastAPI, Flask), Node.js, Java, Scala, APIs, microservices Cloud: AWS (S3, Lambda), serverless architecture Infra: Docker, Kubernetes, CI/CD Data: Spark, Kafka Databases: PostgreSQL, MySQL, MongoDB, Redis 🎯 Typical Projects: • AI chatbot / copilot • RAG over internal/company data • AI SaaS MVP • Full-stack GenAI applications • Workflow automation with LLMs Keywords: Generative AI, GenAI, LLM, GPT-4, GPT-5, Claude, OpenAI API, Anthropic Claude, RAG, Retrieval Augmented Generation, AI Agents, Prompt Engineering, AI Automation, Chatbots, Copilots, Python, FastAPI, Flask, Full-Stack Development, Frontend Development, Backend Development, React, Next.js, TypeScript, Node.js, API Design, REST APIs, GraphQL, Microservices Architecture, SaaS Development, Multi-Tenant Systems, Authentication, OAuth, JWT, Cloud Architecture, AWS, Serverless, Docker, Kubernetes, CI/CD, Distributed Systems, System Design, PostgreSQL, MySQL, MongoDB, Redis, Machine Learning, MLOps, Data Engineering, Apache Spark, Kafka Industries: AI Platforms, SaaS, Enterprise Software, AdTech, MarTech, E-commerce, Marketplaces, FinTech, Payments, Healthcare, HealthTech, Developer Tools, Productivity Tools, Analytics Platforms, Data Platforms, Media, Social Platforms

Full-stack engineer with 6+ years of commercial experience building production web applications. My primary stack is JavaScript / TypeScript with React on the frontend and Node.js / Express on the backend, backed by a solid Java / Spring background for everything that needs heavier server-side logic. I work end-to-end on web products: business logic, REST and WebSocket APIs, database design, frontend implementation, third-party integrations, testing, and deployment. I'm equally comfortable joining an existing codebase and shipping features inside it, or starting a new project from a blank repo. What I do best: 🔹 Full-stack web apps — React / Redux / TypeScript on the frontend, Node.js / Express on the backend, PostgreSQL or MongoDB for data. Clean architecture, REST APIs, real-time features over WebSocket when needed. 🔹 Java / Spring backend — REST APIs, business logic, data access, JUnit + Mockito test coverage. I spent 3+ years on enterprise Java work (Guidewire P&C insurance platform: PolicyCenter, BillingCenter), which taught me how to keep large codebases maintainable and how to ship inside Agile/Scrum teams across multiple parallel projects. 🔹 Complex API integrations & automation — third-party APIs, custom n8n nodes and workflows, Retool internal tools, Google Apps Script. On my most recent project I built a full-stack platform with deep integrations into financial APIs (DeFi protocols via ethers.js, the Bybit exchange, MetaMask), which gave me a lot of exposure to async-heavy systems, real-time data, and reliability work — useful skills that transfer to plenty of non-crypto domains too. What I bring to a project: ✅ End-to-end ownership — from requirements to deployment. ✅ Ability to take over a broken or half-migrated codebase and ship it back to a working state. ✅ Clean, tested, documented code. Unit tests and code review are part of "done," not extras. ✅ Strong API and integration skills (REST, WebSocket, third-party SDKs). ✅ Agile/Scrum communication style — clear updates, realistic estimates, no surprises. Tech stack: Languages: JavaScript, TypeScript, Java, Gosu Frontend: React, Redux, HTML, SCSS/CSS, Tailwind, Material UI Backend: Node.js, Express.js, Spring Framework, Spring Boot Databases: PostgreSQL, MySQL, MongoDB, OracleDB Testing: JUnit, Mockito APIs: REST, WebSocket, third-party API integrations Automation: n8n (custom nodes + workflows), Retool, Google Apps Script DevOps/Tools: Docker, Git, Github, Bitbucket, CI/CD, JIRA, Confluence, Splunk, Postman Also: Web3 / DeFi (ethers.js, AAVE, Uniswap, MetaMask) — available on request Typical projects I'm a strong fit for: — Build a full-stack React + Node.js / TypeScript product from scratch — Add features, fix bugs, or refactor an existing React or Node.js codebase — Design and implement a REST or WebSocket API on Node.js or Spring Boot — Java / Spring Boot backend development and microservices — Frontend work in React (forms, dashboards, admin panels, internal tools) — Third-party API integrations and workflow automation (incl. n8n) — Take over a stalled or messy project and bring it to a working, maintainable state I'm available for both short fixed-price tasks and long-term hourly engagements. If you have a clear spec, a half-finished project, or just an idea you want to scope out — send me a message with a few details and I'll come back with concrete next steps. Keywords: JavaScript, TypeScript, React, React.js, Redux, Redux Toolkit, React Hooks, Next.js, Node.js, Express.js, Express, JavaScript Developer, TypeScript Developer, React Developer, Node.js Developer, Full-Stack Development, Full-Stack Developer, Frontend Development, Frontend Developer, Backend Development, Backend Developer, Web Development, Web Application Development, SPA, Single Page Application, Responsive Web Design, HTML, HTML5, CSS, CSS3, SCSS, Sass, Tailwind CSS, Bootstrap, Material UI, UI Development, UI Components, Dashboard Development, Admin Panel, Internal Tools, Form Development, Java, Java Developer, Spring, Spring Framework, Spring Boot, Spring MVC, Spring Data, Hibernate, JPA, Maven, Gradle, REST API, RESTful API, REST API Development, API Integration, API Design, Third-Party API Integration, Web Services, JSON, WebSocket, WebSockets, Real-Time Applications, Microservices, Backend Architecture, Server-Side Development, PostgreSQL, MySQL, MongoDB, NoSQL, OracleDB, SQL, Database Design, Database Modeling, ORM, JUnit, Mockito, Jest, Unit Testing, Integration Testing, Test-Driven Development, TDD, Code Review, Refactoring, Legacy Code Migration, Codebase Refactoring, Performance Optimization, Bug Fixing, Debugging, Docker, Git, GitHub, Bitbucket, GitLab, CI/CD, GitHub Actions, JIRA, Confluence, Postman, Splunk, Agile, Scrum, Kanban, MVP Development, SaaS Development, Web App Development, Cross-Browser Compatibility, Workflow Automation, n8n, n8n Custom Nodes, Business Process Automation, Retool, Google Apps Script, Google Sheets Automation, Web3,

Your hiring is stuck, or starting from zero, and you want it handled by someone senior who has done it many times. I’m Iia, a recruiter with 12+ years of experience (9 in tech) and 300+ placements across technical and non-technical roles. I run the full cycle for you: I learn your business, build a clear hiring plan, write the job description, source and screen, run first interviews, and deliver a simple scorecard for every candidate. You get weekly updates and full transparency, so you always know where your search stands. I work in two ways, depending on what you need: 1. Hands-on recruiter. I take a role (or a few) and fill it. First strong candidates usually within 3 to 5 business days, most roles closed in 2 to 3 weeks. 2. Fractional Hiring Lead. If hiring is stuck (roles open for months, no clear process), or you have no recruitment function yet, I build the system: process audit, funnel diagnostics, scorecards, SOPs, ATS setup, and salary benchmarking. I can also bring in my recruiters for execution while I oversee quality. What clients rely on me for: • Tech and non-tech roles, from developers, DevOps, QA, and data to SEO, PPC, sales, marketing, and support • A clear “Hiring Map” for each role: sourcing plan, screening criteria, red flags, and funnel targets before sourcing begins • An AI-powered workflow that turns interview transcripts into structured scorecards, saving you time and keeping evaluation consistent I work remote-first and I’m used to international teams. If you’re hiring, send me a message with the role and your ideal candidate, and I’ll tell you exactly how I’d approach it.

I am a senior software engineer with 12 years of extensive experience in full-stack development, primarily utilizing Typescript and React for front-end solutions. My expertise spans a variety of back-end technologies, including Python, Elixir, Go, and Clojure, paired with PostgreSQL for robust database management. I thrive on turning innovative ideas into functional applications, particularly leveraging emerging AI technologies in personal projects. My approach integrates custom state management and efficient app deployment through Docker and Kubernetes. Recently, I have expanded my skill set into data engineering using Apache Spark and Databricks. If you are looking for a creative problem solver who can navigate complex challenges and deliver high-quality software solutions, let's connect and discuss how I can contribute to your project.

✅ Expert Vetted & Top Rated Plus Freelancer ✅ 100% Job Success Score ✅ Smartsheet Aligned Sales Professional Certified ✅ Smartsheet Aligned Solution Consultant & Professional Certified ✅ Smartsheet Integration Specialist ✅ Helped 100+ companies in the implementation of Smartsheet. 13+ years of experience working as a Project Manager, Agile Scrum Master, Smartsheet Consultant, and API services Architect. I have strong experience in Software Architecture Design. My skill sets include: 🌟 Smartsheet Core, Advance, Add-ons: ✔ Smartsheet AI Solutions ✔ Core App Solutions ✔ Control Center ✔ Resource Management ✔ Dynamic View ✔ Pivot App ✔ Data Shuttle ✔ Data Mesh ✔ Data Table ✔ Calendar App ✔ WorkApps ✔ Brandfolder ✔ Bridge ✔ Zapier Integration ✔ Salesforce Connector ✔ JIRA Connector ✔ Microsoft Dynamics 365 Connector 🌟 Smartsheet Custom API Integrations ✔ Integration with Google Sheets ✔ Integration with Salesforce ✔ Integration with Custom DB like PostgreSQL, MySQL, MSSQL ✔ Integration with JIRA 🌟 Project Management: ✔ Agile Scrum Master ✔ Sprint Specialist ✔ Remote team handling ✔ Smartsheet Reporting ✔ Smartsheet Project Plan ✔ Smartsheet Project Status Dashboards updating automatically. ✔ Smartsheet advanced apps like Control Center, Resource Management I believe in long-term relationships with clients and always prefer repetitive work. Contact me with your requirements. Tags: smartsheet, smartsheet expert, smartsheet professional,smartsheet solution, control center, Brandfolder, resource management, smartsheet advance, dynamic view, brandfolder, zapier, smartsheet certified, dynamic view, data table, data mesh, project management, smartsheet integration, smartsheet api, multi-tier, project management, integration Thanks, Sudhir Jain

I have about a year of professional experience, mostly in back-end development, where I worked on various web applications and APIs. I primarily used Java and Kotlin with Spring Boot, as well as JavaScript/TypeScript with Node.js and Express. I’ve also had the opportunity to work with the Next.js framework on projects that required a full-stack approach, where I used Material UI (MUI) for building user interfaces. Through that, I gained a solid understanding of working with React. I’ve worked with databases such as PostgreSQL, MySQL, MongoDB, Firebase, and Snowflake – from creating and maintaining databases, writing queries and migrations, to deployment and optimizing data performance. Lately, I’ve been increasingly involved in DevOps tasks: I’ve built CI/CD pipelines using GitHub Actions and Jenkins, used SSH to connect to remote servers, worked daily in a Linux environment via the command line and tools like Termius, and I have plenty of experience working with containers using Docker and Docker Compose. I also often use NGINX for configuring reverse proxies, serving applications, and managing access in production environments. Additionally, I’ve worked with many other tools and technologies that I haven’t mentioned here, and I’d be happy to share more about my experience depending on what specifically interests you. Feel free to check out my GitHub profile, where you’ll find examples of some of the technologies mentioned above and more

Clojure/Racket/Emacs-Lisp, Mathematica, Python/Julia/R, C++/Rust, Haskell, Typst, Linux. Please find more at killianz.com.

Extensive experience with n8n, make.com(lvl 5 cert), and python. Languages: java+clojure(for fun), python, js