Top Rated full-stack developer — $70K+ earned, 1,643+ hours, 94% Job Success across 68 Upwork projects. I lead a 30+ person engineering team at Craxinno Technologies (founded 2017). We've shipped 100+ web apps, mobile apps, and digital products for founders, agencies, and enterprise clients worldwide. Our core stack: React, Next.js, Node.js, TypeScript, Express.js That's where we spend most of our time. We build fast, type-safe, SEO-friendly web applications, SaaS dashboards, internal tools, and marketing sites that hold up at scale. Our own site runs on Next.js + Node.js + TypeScript — we use what we ship. Technologies we work with daily (across 109+ in our stack): • Frontend — React, Next.js, TypeScript, JavaScript, Tailwind CSS, Redux, Zustand, HTML5, CSS3, SASS • Backend — Node.js, Express.js, NestJS, REST APIs, GraphQL, WebSockets • Databases — PostgreSQL, MongoDB, MySQL, Redis, Firebase, Supabase, Prisma • DevOps & Hosting — AWS, Vercel, Docker, CI/CD, GitHub Actions, Nginx • Mobile — React Native, Flutter, Swift, Kotlin • CMS & E-commerce — WordPress, Elementor Pro, Shopify (Liquid, custom apps) • Design — Figma, Adobe XD (UI/UX design, prototyping, design systems) • QA — Jest, Playwright, Cypress, Postman Services we offer 1. Web App Development — Next.js / React SaaS, dashboards, internal tools, marketing sites 2. Mobile App Development — React Native, Flutter, and native (Swift / Kotlin) builds 3. UI/UX Design — Figma-first design with pixel-perfect handoff to code 4. API & Backend Development — Node.js / Express / NestJS APIs, third-party integrations 5. E-commerce — Shopify storefronts and custom apps 6. WordPress — pixel-perfect Figma-to-Elementor Pro builds when CMS flexibility matters 7. DevOps & Maintenance — AWS/Vercel deployment, monitoring, ongoing support Why clients keep coming back • Strong, type-safe codebases — TypeScript end-to-end means fewer production bugs and easier handoffs • Pixel-perfect from Figma — your design is the spec, not a suggestion • Async-friendly delivery — Loom walkthroughs at each milestone, 0–4 hour response time • A full team behind one point of contact — you talk to me, but you get the bandwidth of a 30+ person studio • 5-star reviews across the board — clients consistently call out communication, speed, and clean code Let's talk Whether you have a Figma file, a half-built repo, or just an idea — send it over. I'll review it and tell you honestly whether we're the right fit and how I'd approach it. Thanks for reading, Nimish Taneja Founder, Craxinno Technologies

🏆 15+ Years Experience | 1M+ App Downloads If you’re looking for top-quality App development, not just average work — you’ve come to the right place. I build high-performing, scalable, and beautifully crafted Mobile, Web & Desktop apps that clients rely on for the long term in real quick time using AI & LLM tools. With 15+ years of experience and apps exceeding 1 Million+ downloads on the Play Store, I’ve worked with startups and established brands to turn complex ideas into stable, user-loved apps. Clients stay with me because I focus on code quality, performance, and results — not shortcuts. ⸻ 💡 What I Offer ✅ Production-ready apps ✅ Clean, modular, and testable architecture ✅ Clear communication & reliable delivery ✅ Long-term collaboration and maintenance support ⸻ ⚙️ Technical Expertise Flutter & Dart: Riverpod, Provider, BLoC React & React native Testing: Unit, widget, and integration tests AI Integration: ChatGPT & Google Gemini Chat Systems: 1-to-1 & group chat with voice, video & attachments Video Calling: Conferencing via LiveKit / WebRTC Maps: Google Maps & vector maps Deep Linking: App Links & Universal Links Analytics: Google Analytics, Amplitude Marketing: Appsflyer Payments: Stripe & in-app purchases Ads: Google Ads integration Firebase Suite: Auth, Firestore, Storage, Messaging, Functions, Hosting, Dynamic Links, Remote Config, App Distribution Supabase Suite: Auth, Database, edge functions, storage ⸻ 🚀 Let’s Build Something Exceptional I take pride in my work — every line of code reflects that. If you want a developer who values quality, communication, and craftsmanship, let’s connect and discuss how I can help bring your vision to life.

I build production-ready web apps, mobile apps, and AI-powered systems, not just prototypes that break later. From idea to deployment, I help you turn your concept into a scalable, fast, and user-friendly product with clean architecture and real-world usability. 𝐖𝐡𝐚𝐭 𝐈 𝐂𝐚𝐧 𝐁𝐮𝐢𝐥𝐝 𝐟𝐨𝐫 𝐘𝐨𝐮: - Full Stack Web Apps (Next.js, React, TypeScript) - Mobile Apps (Flutter, Kotlin – Android & Cross-platform) - Backend Systems & APIs (Node.js, Express, Firebase) - AI Chatbots & AI Agents (OpenAI, Vapi, custom workflows) - Document-based AI (Chat with PDFs, knowledge systems) - E-commerce & SaaS Platforms - Automation & Integrations 𝐇𝐨𝐰 𝐈 𝐖𝐨𝐫𝐤 (𝐂𝐥𝐞𝐚𝐫 𝐏𝐫𝐨𝐜𝐞𝐬𝐬 = 𝐁𝐞𝐭𝐭𝐞𝐫 𝐑𝐞𝐬𝐮𝐥𝐭𝐬): Instead of jumping straight into code, I follow a structured approach: Understanding your idea → Goals, users, and expected outcome Planning → Scope, timeline, and best tech choices UX & Flow Design → Simple and user-friendly structure Development → Clean, scalable, and optimized code Testing & Deployment → Stable launch with real-world performance 𝐌𝐲 𝐓𝐞𝐜𝐡 𝐒𝐭𝐚𝐜𝐤: Frontend: React, Next.js, TypeScript, JavaScript, HTML/CSS Backend: Node.js, Express.js, Firebase, REST APIs Mobile: Flutter, Kotlin, Java AI/ML: Python, OpenAI APIs, AI agents, automation systems 𝐖𝐡𝐲 𝐂𝐥𝐢𝐞𝐧𝐭𝐬 𝐂𝐡𝐨𝐨𝐬𝐞 𝐌𝐞: I focus on solutions, not just coding I recommend better, faster, or cheaper approaches when possible I build systems that are scalable and maintainable Clear communication & on-time delivery 𝐆𝐨𝐭 𝐚𝐧 𝐢𝐝𝐞𝐚 𝐨𝐫 𝐩𝐫𝐨𝐣𝐞𝐜𝐭? Send me a message with what you're building, I’ll help you scope it, suggest improvements, and plan the best way to launch it.

🟢 AVAILABLE TODAY, JUNE 30 ⚡ Message me "AUDIT" - get a free 30-min technical review of your app idea, architecture, or existing codebase. No sales pitch. Just honest engineering feedback. I'm Siarhei - ex-CTO × 3 funded startups, CEO of Sparkler Soft. We build native iOS & Android products that ship, scale, and raise. 🔵 PROVEN RESULTS ◈ iHairium - AI Hair Diagnostics (live on App Store) Neural network · 100K+ training images · 95-98% accuracy $600K angel round + $5M seed valuation Revenue ×10 to ×1000 per month in early stages Google & Amazon grants · 1,000+ clinic partners onboarded ◈ Eco-Go - Electric Scooter Sharing Platform iOS + Android + Backend + IoT + Admin Panel AWS IoT Device Management · Swappable battery infrastructure Named "Best Startup of the Region" ◈ Optics Platform [White-label · Strict NDA] AI-assisted frame & lens selection via device camera Active in 60+ countries · 1,000+ fitting points worldwide 10+ years on market · Award-winning at international exhibitions ◈ Chibbis - Unified Food Delivery Service 600+ restaurants · 150+ cities across Russia iOS + Android + Web + Admin Panel + CMS One of the country's leading delivery platforms ◈ CoinForShop - Crypto Marketplace iOS + Android + Web (React) Non-custodial wallets · Smart contract payments BTC · ETH · BCH · LTC · XMR · TRX · 100% MVP delivered ◈ Azarium - NFT Real Estate Investment Platform Fractional property ownership via blockchain MAS-regulated · Live construction webcam in-app Min investment from $200 · Expected ROI 30–60% 🟠 WHAT WE BUILD → HealthTech & AI On-device ML · Camera diagnostics · Neural networks TensorFlow Lite · Core ML · OpenCV → FinTech & Crypto Wallets · KYC/AML · Stripe · Smart contracts · NFT → Mobility & IoT GPS · BLE · AWS IoT · Scooter & bike sharing Telematics · Real-time fleet management → Marketplace & Delivery Full-stack: app + backend + admin panel + CMS → API Integrations Stripe · Mapbox · Sumsub · Firebase · any third-party 🟡 TECH STACK Mobile: Swift · SwiftUI · Objective-C · Kotlin · Java Backend: Java Spring Boot · Node.js · NestJS · Golang Frontend: React · Next.js AI/ML: TensorFlow Lite · Core ML · OpenCV Cloud: AWS · GCP · Azure · Docker · Kubernetes · CI/CD Data: PostgreSQL · MongoDB · Redis · Elasticsearch Security: OAuth2 · OIDC · JWT · Keycloak · Biometrics · IAP 👉 Message "AUDIT" right now - 30 minutes to understand if we're the right fit. No obligation. No pitch. Just clarity.

Do you remember that scene in Pulp Fiction when Jules and Vincent are in a car covered in blood with a dead body in the backset, absolutely freaking out, and they have to call Mr. Wolf? He steps in, gets to the job site in record time, takes control of the situation and cleans up the mess that nobody else had any idea how to deal with. Or how about Saul Goodman in Breaking Bad when he leans in and says, "I know a guy... who knows a guy." Well on Upwork, I am that guy. Except instead of cleaning up crime scenes, I help companies navigate high-stakes, complex technical challenges across the modern web. I am the fixer you call when you’re dealing with intricate integrations, tricky third-party vendors, sometimes entirely undefined scenarios that require a steady hand. I’m the guy you call when your developer walks off the job because he doesn’t know how to communicate with other types of humans, or when they've forgotten that the actual purpose of a building a web app is to serve customers; not to build some monument to their own "ideal architecture" or experiment with a trendy new framework on your dime. Here is what I bring to the table: - Emergency Navigation: I step into high-stress, broken scenarios and stabilize them quickly. - Autonomous Problem Solving: You don't need to hand-hold me. I take complex, messy problems and carry them forward on my own. - Reliable Backup: I can seamlessly plug into your existing pipeline when your internal team is bottlenecked. 
 A few real-world problems I've solved recently:

 - advising, guiding and informing a CEO to uncover massive memory leaks across 5K web modules and teaching him and his 100 member dev team about memory profiling and how to ship code in a huge team with best practices so it won't happen again - fixing thorny analytics problems that span multiple Astro websites with platforms like TripleWhale, Stripe, LineUp, GTAG and Blotout for a famous London theatre company - took ownership of a complex, legacy app as a full stack lead web developer for over a year of a provincially run teaching platform in Canada that used frameworks that no one has ever heard and were completely undocumented - revolutionizing the way a 24M ARR company ships frontend code by building a proxying bundler that could bundle local code against any production server by modifying how a web browser functions If your project is off the rails, your deadline is ticking, or you just need an expert full-stack web developer that knows what they are doing, let’s talk. Drop me a message with your current bottleneck, and let’s see if I’m the right man for the job.

Experienced and passionate CTO, VP of Engineering, tech lead, and serial entrepreneur. Fractional CTO/Tech lead that supports you, your project, and your company in every timezone. Get help with architecture, development, team management, DevOps, building decentralized load-balanced infrastructure, and everything in between. 👌 Expertise in: - Team building and training - Software development methodologies - Financial services, transaction processing, card issuance and management - Banking APIs, payment services integrations, SEPA, IBAN - Disaster recovery - General consulting on Open Source, Web Apps, Servers, backend, micro-services, horizontal scaling, high-load, DevOps, OpSec - Planning architectures for future websites/apps/servers aligned with business goals 📈 Achievements: - Scaled software development company from 30 to 200 developers ensuring all teams can work in parallel with TOP performance (2024-2025) - NeoBank: Built team, guidelines, compliant infrastructure, and launched modern banking application from 0 to issuing cards to users within 9 months; Went through Visa and MasterCard accelerators (2022-2024) - IT Consulting services: Built efficient team that follows strict security and best practices guidelines (since 2016) - Deep-tech SaaS: Built team and service with globally distributed CDN (HL, HA) (since 2015) - Government services app: Managed team, built guidelines and compliant software for the GovTech that used by 1m+ daily users (2013) - Live-streaming service: Built team, infrastructure, and video service (VoD & RTMP) used by 2 millions simultaneous users (2012) 👷‍♂️ DevOps: - Horizontally scaled and distributed infrastructures - Co-located bare-metal servers, Web-servers, Could - High-load, high-availability, and cross-border infrastructure - Databases & Linux web servers clusters, shards (horizontal and vertical scaling) - Custom automated deployments & backups - Consultancy about protection against DDoS, hacks, and other attacks 👨‍🏫 Mentorship (for individuals and companies): - Education - Project/Team mentorship - Pair-programming - Code-review - Guidelines and best-practices application - Project planning - Architecture planning 🎙 Speaker: - Meteor Impact 2025 - Meteor Impact 2020 - DeveloperWeek 2019 🤝 Social & Open Source: - GitHub: @veliovgroup - GitHub: @dr-dimitru - NPM: @dr.dimitru - Atmosphere/Packosphere: @ostrio - StackOverflow: @dr-dimitru - Twitter: @smart_egg