zavada

the engineer runtime

Hire me directly. I stay on the product.

FinTech & HighLoad, SaaS & AI, React, Next.js, Node.js, Telegram Mini Apps

Dmytro Zavada, Senior Full-Stack Engineer / Software Engineer. 11+ years in tech and a Master's in Computer Science. FinTech, HighLoad, $1.5M+ processed volume. Available globally. I help startups, founders, and engineering teams build production-grade web applications from scratch - React, Next.js, Node.js, TypeScript, SaaS, AI & FinTech. I take long-term retainers: you work with me after launch, not a two-week handoff. No agency, no juniors.

mail zavada.dmitry@gmail.com

macOS · Linux · Windows · available globally · remote B2B - email, Upwork, or the form →

Let's discuss detailsUpwork
Dmytro Zavada

Dmytro Zavada

Kyiv, Ukraine

availableworking

❯ whoami

Dmytro Zavada

Senior Full-Stack Engineer / Software Engineer

long-term · now

Available globally - long-term remote B2B, can start now

❯ _

Click a row in spaces - availability and the career. I stay on the product.

Social Links

upwork→linkedin→github→email→

11+

years of experience

$1.5M+

processed volume

Years

not sprints - long-term

100%

hands-on - no juniors

Hire me for

SaaS, Mini Apps, and AI - long-term senior execution, not an agency handoff.

  1. 01

    Website development. →

    Marketing and product sites on Next.js - pixel-perfect, mobile-first, Core Web Vitals as a requirement, not a later ticket.

  2. 02

    SaaS & web apps. →

    From DB design and NestJS to polished Next.js - dashboards, marketplaces, fintech, CRM, booking, e-learning.

  3. 03

    Telegram Mini Apps. →

    Mini Apps, payment bots, TWA - Next.js inside Telegram. Last shipped: a Mini App under NDA.

  4. 04

    AI in the product. →

    LLM integrations (OpenAI, Anthropic), RAG, TTS / audiobook pipelines, automation - a step in the product, not a demo chat.

About

I don't just write code - I build production-grade products.

Ready to get started? Send me a message - I'm available to start now. Let's discuss your project, requirements, and the best way to move forward.

With 11+ years in tech and a Master's in Computer Science, I help startups, founders, and engineering teams build production-grade web applications from scratch.

FinTech, HighLoad, $1.5M+ processed volume on live payment systems. I look for long-term retainers: I ship v1 and stay. Visiting Media for three years. Upwork product delivery from 2017 to 2025. Not a two-week dump.

100% Hands-On: you work directly with me. No agency bloat, no hidden outsourcing, and no hand-offs to junior devs. You get senior-level architecture and execution on every line of code.

Full Product Ownership: from DB design and NestJS backends to polished Next.js interfaces and AI integrations. Polished React interfaces, robust backends, and modern technologies like AI and DevOps come together as one product.

Recent path: Senior Software Engineer on an NDA fintech Mini App (Aug 2025–present), Senior Full Stack at Visiting Media (2022–2025) and Upwork (2017–2025), ETNA Network, Team Lead at Siteplus, and a Master's in Computer Sciences at the University of State Fiscal Service of Ukraine.

If you're looking for a senior full-stack engineer to join for the long run, contribute beyond code, and help build a product that lasts - message me today.

What I take on

  • 11+ years shipping production products: SaaS platforms, investor-ready MVPs that survive the next hire, dashboards, marketplaces, booking, FinTech and HighLoad systems ($1.5M+ processed volume), EdTech / LMS, CRM/ERP, hospitality sales tools, and Web3 / DeFi / GameFi.
  • Full product ownership, not a ticket slice: data model and APIs (NestJS or Node + Express, GraphQL / REST), Prisma, Postgres / Mongo / Supabase - then a TypeScript-first React / Next.js UI (SSR, SSG, ISR, hybrid).
  • Frontend at senior depth: React Query, MobX, Zustand, Redux Toolkit; code splitting, lazy loading, Suspense; pixel-perfect mobile-first UI on Tailwind, MUI, SCSS; Jest, Cypress, Vitest, Playwright.
  • Telegram Mini Apps and payment bots - TWA, product UI and checkout where the user already lives. Last shipped: a fintech Web & Mini App under NDA (virtual / physical cards, Next.js + Express + Mongo).
  • AI as a step in the product, not a landing-page chatbot: LLM integrations (OpenAI, Anthropic), RAG, in-app assistants, Text-to-Speech (StyleTTS2), audiobook pipelines, and workflow automation.
  • React Native when the same product needs iOS and Android - shared logic with the web app, not a second rewrite from scratch.
  • Delivery I stay on after v1: Docker, GitHub / GitLab CI, AWS, Vercel / Netlify, scraping (Playwright, Puppeteer), Web3 (Ethers.js, Web3.js, Crossmint) when the domain actually needs it.
  • Direct B2B contractor, remote globally, available to start now. Default engagement is long-term: retainer after launch, not a two-week handoff. You work with me - no agency layer, no junior dump. I stay accountable after the first deploy.

Stack

TSTypeScriptRReactNNext.jsNoNode.jsNeNestJSPgPostgreSQLPrPrismaRQReact QueryDkDockerGqGraphQLMgMongoDBTwTailwindTSTypeScriptRReactNNext.jsNoNode.jsNeNestJSPgPostgreSQLPrPrismaRQReact QueryDkDockerGqGraphQLMgMongoDBTwTailwind
SbSupabaseJeJestCyCypressAIOpenAIPwPlaywrightRNReact NativeAWAWSViViteRxReduxZuZustandEthEthers.js▲VercelSbSupabaseJeJestCyCypressAIOpenAIPwPlaywrightRNReact NativeAWAWSViViteRxReduxZuZustandEthEthers.js▲Vercel

Skills

Senior full-stack execution - from NestJS backends to Next.js UIs, AI, scraping, and Web3.

Backend

  • ✓Node.js (NestJS), GraphQL, REST, Prisma ORM, Supabase, microservices
  • ✓HighLoad, high-performance architecture - from a single API to distributed services

Frontend (React ecosystem)

  • ✓React.js / Next.js (SSR, SSG, ISR, Hybrid) - TypeScript-first
  • ✓React Native for iOS & Android, code sharing with web
  • ✓State: React Query, MobX, Zustand, Redux Toolkit, Context API
  • ✓Performance: code splitting, lazy loading, memoization, Suspense
  • ✓Testing: Jest, Cypress, Vitest
  • ✓UI: Alpine.js, Tailwind, MUI, SCSS - pixel-perfect, mobile-first

AI

  • ✓AI chatbot creation, LLM integrations (OpenAI, Anthropic)
  • ✓Text-to-Speech (StyleTTS2), audiobook generation, AI-driven automation

MERN & data

  • ✓MongoDB, Postgres, Express.js, React.js, Node.js - full-stack with seamless integration
  • ✓Web scraping: Playwright, Puppeteer

CI/CD & DevOps

  • ✓Vite, Webpack, Gulp, Docker, GitHub/GitLab CI, Vercel / Netlify

Products & Web3

  • ✓SaaS, dashboards, marketplaces, FinTech / HighLoad, e-learning, CRM/ERP, DeFi/GameFi
  • ✓MVPs that scale: raw idea → production-ready product
  • ✓Web3: Ethers.js, Web3.js, Crossmint, Blockradar, Nexus

Core Expertise

Senior Full Stack Engineering • React Development • Next.js Development • Node.js Development • MERN Stack Development • SaaS Development • Product Development • Startup MVP Development • AI Integrations • TypeScript • JavaScript • Scalable Web Applications • Enterprise Applications • HighLoad • FinTech • "$1.5M+" processed volume • Long-term retainer • "Senior Full Stack Developer" React Next.js Node.js • "Next.js Developer" TypeScript AI • "AI Integration" React Next.js • "AI Engineer" "Next.js" Node.js • "Product Engineer" React TypeScript • "Senior React Developer" Next.js • Senior Software Engineer • Full Stack AI Developer • AI Full Stack Developer • FinTech Developer

Projects(selected)

All projects →

Product systems under NDA

Some client names and URLs stay off this page. The shape of the work is fair to describe: international SaaS, payments, and ops products.

  • Large-scale product work: marketplaces, FinTech / HighLoad ($1.5M+ processed volume), e-learning, CRM/ERP, DeFi/GameFi, SaaS
  • Full-stack ownership: Postgres / Mongo, NestJS or Node APIs, React / Next.js, CI on Docker
  • Telegram Mini Apps and bots - payments and product UI where the user already lives
  • AI inside the app: LLM hooks, RAG, TTS - not a landing-page chatbot

Selected work

Telegram Mini App

Senior Software Engineer · NDA · 2025–present

FinTech HighLoad Web & Telegram Mini App - virtual/physical cards, $1.5M+ processed volume. Next.js, Node.js + Express + MongoDB, Playwright. Client name withheld.

TelegramMini AppNext.jsNDA

Visiting Media

Senior Full Stack · 2022–2025

Hospitality sales-enablement SaaS for hotel brands. React, Next.js, TypeScript, tests, and a production AWS / Docker path.

Next.jsReactTypeScriptAWS

Upwork - product delivery

Senior Full Stack · Upwork · 2017–2025

Long-term retainers and investor-ready MVPs: SaaS, dashboards, marketplaces, booking, LMS, CRM, Web3 - I ship and stay, from the data model to years after deploy.

ReactNode.jsNestJSAI

Frequently asked questions

Answers to common questions about working together

For a marketing site we start from the brief or Figma. For product work we start from the domain: business rules, data model, existing APIs. Then architecture, milestones, iterative delivery with updates, QA, and deploy. You work with me directly - no middle managers.

Yes. I sign a standard NDA before we discuss confidential product details or share source. Visiting Media and other client systems stay behind that line on this site.

Frontend: React, Next.js, TypeScript, React Query / Zustand / MobX / Redux, Jest / Cypress / Vitest, MUI / Tailwind. Backend: Node.js, NestJS, GraphQL / REST, Prisma, Postgres / Mongo / Supabase. Also Telegram Mini Apps, AI (OpenAI, Anthropic, RAG, TTS), and React Native when the same product needs a phone.

Send a short brief - what you need, a deadline if you have one, links or Figma. Email, LinkedIn, or Upwork. I am available to start now. Then a fixed-price estimate or an hourly start - and a retainer if you want me to stay.

Long-term is the default. I ship the first version, then stay - retainers in months and years, not a two-week dump. Visiting Media was three years. Upwork product work ran from 2017 to 2025. I can start now and I plan to stay.

Yes. Remote B2B globally, including Ukrainian teams. We can agree on a contract and invoicing that fits both sides.

Architecture and MVPs that scale, performance, full-stack debugging, AI and Telegram where they earn their keep - and I stay on the product after the first deploy.

Give the next product someone who stays.

Ready to get started? Send me a message - I'm available to start now and to stay. Long-term retainers, not a two-week handoff. Let's discuss your project, requirements, and the best way to move forward.

mail zavada.dmitry@gmail.com
Get in touchHire me on Upwork