I build things that make sound in the browser — from scratch. My current project, blzr.app, is a visual node-based audio synthesizer running entirely in the browser. I designed and built it solo: the DSP engine (Web Audio API + custom AudioWorklet processors), the node graph editor, the module system, MIDI integration — the full stack. It's live, it works, and it proves I can ship complex audio software independently. What I bring to your project: → DEEP WEB AUDIO EXPERTISE Custom AudioWorklet nodes for sample-accurate processing. Oscillators, filters, delays, reverbs, compressors, distortion — I've implemented them all as modular, connectable nodes. I understand the Web Audio API at the spec level, not just the tutorial level. → FULL-STACK DELIVERY Nearly 10 years of professional software development. Background in telecom engineering (Warsaw University of Technology), 3.5 years at CodiLime building production systems, plus consulting and advisory roles in AI. ClojureScript, JavaScript/TypeScript, React, Python, PostgreSQL, AWS — I pick the right tool for the job. CI/CD pipelines, deployment automation, the whole lifecycle. You get a working product, not a prototype that needs "just a few more sprints." → INTERACTIVE AUDIO FOR ANY CONTEXT - Browser-based synthesizers and instruments - Audio visualization and analysis tools - Real-time audio effects and processing - Educational/tutorial audio applications - Game audio systems (Web Audio + WebGL/Canvas) - Sound design tools and generative audio → AI-AUGMENTED DELIVERY As an active AI tech advisor, I use AI coding tools strategically to deliver faster without sacrificing quality. This means shorter timelines and more iterations within your budget — not sloppy generated code, but AI-accelerated expert work. I work from Poland (CET timezone), communicate in fluent English, and I'm available for both short-term builds and ongoing engagements. See the live demo: blzr.app

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.

I am a Senior Full Stack Engineer with 9 years of experience building high-concurrency, real-time platforms in the sportsbook, banking, and streaming industries. I specialize in both backend and frontend development, optimizing resilience and performance to handle up to 2 million concurrent users during peak events. My expertise encompasses a core stack of TypeScript, Node.js, React, and Angular, including significant projects like a 40% faster initial load through Angular migration and a re-architecture using Astro. I excel in event-driven processing, observability, and implementing TDD in CI/CD environments. If you are seeking a technically proficient engineer who can deliver scalable solutions and enhance user experiences, I am ready to bring your vision to life. Let’s discuss your project and explore how I can contribute to your success.

I'm a senior software engineer with a background spanning technical support, application debugging, DevOps, automation, and software development. I help companies troubleshoot production issues, automate manual processes, and improve the reliability of their software systems. I specialize in diagnosing complex technical problems and turning manual, error-prone processes into reliable systems. My experience includes debugging Java applications, analyzing production issues, automating workflows, building internal tools, improving deployment pipelines, and helping teams identify the root cause of difficult software problems. Unlike developers who focus solely on building new features, I've spent years investigating real-world issues in production environments. That experience has made me comfortable working with unfamiliar systems, reading logs, tracing failures, identifying bottlenecks, and delivering practical solutions quickly. Areas I can help with include: • Application troubleshooting and root-cause analysis • Java application debugging • DevOps and CI/CD improvements • Infrastructure and deployment automation • Scripting and workflow automation (Python, Bash, etc.) • Log analysis and production support • Internal tools and operational efficiency projects • API integrations and backend development Whether you need help fixing a stubborn issue, automating a repetitive process, or improving the reliability of your systems, I bring a methodical, problem-solving approach focused on results rather than buzzwords.

As a senior technology professional, I excel in seeking simplicity and novelty in my projects and partnerships. With extensive experience in programming, I possess a deep understanding of advanced AI tools and creative meta-models. My strengths include designing robust solutions, developing innovative applications, and directing strategic initiatives.

I am a back-end engineer with over 7 years of experience in developing scalable server-side applications. My expertise lies in Python, with a strong command of frameworks like Django, FastAPI, and Flask. I excel in database design, API development, and microservices architecture, ensuring high performance and security in every project. I integrate third-party services seamlessly and prioritize clean code and test-driven development. My passion for continuous learning keeps me at the forefront of software engineering best practices. If you need a professional who can deliver robust back-end solutions tailored to your unique challenges, let's discuss your project and explore how I can contribute to your success.

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,

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!

Principal Architect with 25 years building software — from trading firm infrastructure to SaaS products to leading engineering teams through IPO. I ship fast. Complex systems that other devs struggle with for months, I deliver in days. I've spent decades solving hard problems: real-time trading systems, distributed architectures, AI integrations, and everything in between. What I do best: - Full-stack development: React, TypeScript, Node.js, Rails, Elixir, Python, GoLang, distributed programming, event-driven programming. - AI integration: OpenAI, Claude, LLM-powered features and automation. - Agent & LLM Creation: I love working with vector databases, working on agents, and creating new concepts with Ai. - Cloudflare & serverless: Workers, D1, Durable Objects, edge-first architecture - AWS/GCP/Azure: I have been working in these domains since their inception - Rescue jobs: fixing broken systems, untangling tech debt, shipping stalled projects Performance & Reverse Engineering: I love fixing performance issues, reverse-engineering challenges, and cleaning up code bases. - UI & UX: I love Figma, I love creating amazing ui's for desktop and mobile, user experience and amazing user interfaces is my "jam." I love making video games both native and in the browser with Three.js & GSAP. I'm one of the weird CSS lovers :) Background: Senior Engineering Manager at Procore (through IPO), Principal Architect at FAANG & trading firms, CTO roles. I am currently running a boutique consultancy building and launching challenging and interesting products. I'm not the cheapest option. I'm the one who gets it done right, fast, and without hand-holding.

✅ 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