Senior Full-Stack Engineer · AI Native

Nikita Beznosikov

Senior Full-Stack Engineer with 9 years building web products end to end — checkout flows, payment integrations, admin tooling, and full e-commerce systems. Strongest in React, Next.js, Node.js, and TypeScript.

I owned the engineering for a US-based e-commerce business reaching ~$1M/month and ~2,000 orders/day — React checkout SPA, Node.js services, admin tooling, and 50+ live offers running 3–5 A/B variations in parallel.

Currently shipping independent web, App Store, and Shopify App Store products. I work best with real ownership — picking the approach, building both ends, integrating services, and supporting what I ship.

AI-native workflow with Cursor, Claude, and GitHub Copilot — parallel agent sessions across branches for independent workstreams.

Madrid, Spain Open to relocation · DE · NL · UK
E-commerce Checkout Internal tooling Shopify apps Payments React Next.js Node.js TypeScript
01 · Selected work

Selected work

Independent web, App Store, and Shopify App Store products, plus production work and technical demos across checkout, payments, analytics, and internal tools.

Kairos — AI Job Search Workspace

AI product Job search Pipeline tracking

AI workspace built during my own search: paste a job posting and get a fit score against your CV, skills, salary, and work-auth constraints.

Built

  • Job-posting fit score against CV, skills, salary, and work-auth constraints
  • Cover letter, recruiter Q&A, and cold outreach generation
  • Critic pass to strip out chatbot tells
  • Application pipeline tracking in one workspace
  • AI-native workflow built around a real job search

Stack

Next.jsSupabasePrismaGemini FlashRailwayTypeScript

PassportPro — Shopify Digital Product Passport App

Shopify app EU compliance QR passports

Shopify app for EU Digital Product Passport / GPSR workflows.

Built

  • QR-based product passports
  • Merchant admin interface
  • CSV bulk editing
  • AI-assisted autofill
  • Shopify product-page integration
  • Configurable passport data model

Stack

ShopifyRemixNode.jsPrismaShopify GraphQL APIQR PassportsAI Autofill

CreditReel — Pay-per-use Video Testimonials SaaS

SaaS product Stripe billing Video

SaaS platform for collecting text and video testimonials through shareable links, without subscriptions.

Built

  • Video recording flow
  • Text and video review collection
  • Stripe credit-based payments
  • Business dashboard
  • Embeddable testimonial widgets
  • Cloudflare Stream video delivery

Stack

Next.jsSupabase / PostgreSQLStripeCloudflare StreamSaaS

InstaDeck — iOS AI Flashcard App

iOS app React Native LLM

React Native iOS app that generates flashcard decks from any topic using LLMs, graded easy to hard.

Built

  • Prompt-based deck generation
  • Spaced repetition
  • Offline-first SQLite storage
  • Freemium app flow
  • App Store release

Stack

React NativeTypeScriptSQLiteLLMiOS

GMC Store Readiness Scanner — Shopify Audit Tool

Public Shopify app Compliance tooling

Shopify app that audits stores for Google Merchant Center readiness before merchants submit products for review.

Built

  • Automated store-readiness checks
  • Product data validation
  • Policy and checkout checks
  • Readiness score
  • Prioritized issue list for merchants
  • Shopify admin workflow

Stack

ShopifyRemixPostgreSQLShopify APIMerchant CenterAuditing

Manna — Custom E-commerce Platform

Production work E-commerce Checkout

Custom storefront built from scratch after Shopify proved too limited for the company's checkout, upsell, subscription, and A/B testing requirements.

Built

  • Next.js storefront
  • Node.js backend
  • Custom checkout flow
  • Subscription billing integration
  • CMS / admin panel for products, banners, and content
  • Customer portal with Firebase Auth (login, registration, order history)
  • Payment and order-management flows
  • Server-side conversion tracking

Stack

Next.jsNode.jsFirebase AuthCheckoutPaymentsCMS
Technical demos

Demos I built to explore patterns relevant to my work.

Payment System Demo

Payment orchestration patterns — multi-provider routing, retry logic, order state transitions, and SSE event streaming.

Node.js · TypeScript · Express · PostgreSQL · SSE

Analytics Dashboard Demo

50k synthetic orders, downsampled time-series charting, virtualized server-side filtered table, KPIs with period-over-period deltas.

Next.js · React · TanStack · Recharts

AI Feature Demo

Review analyser: bounded LLM call returning Zod-validated structured sentiment, with Cloudflare Turnstile protecting the cost surface.

Next.js · Gemini · Zod · Turnstile
02 · Career

Experience

2025 — Present
Remote
Independent Engineer
Shipping independent products end to end

Designing, building, shipping, and supporting my own web, App Store, and Shopify App Store products — both ends of the stack, all integrations, all the way to live customers.

  • Kairos (getkairos.fyi, GitHub) — AI job search workspace: fit scoring against CV, skills, salary, and work-auth constraints, cover letters, recruiter Q&A, cold outreach, critic pass, and application pipeline tracking.
  • PassportPro (passportpro.app) — Shopify app for EU Digital Product Passport compliance: QR-coded passports, label printing, product-page integration, AI auto-fill, CSV import.
  • CreditReel (creditreel.to) — pay-per-use video testimonial SaaS. Businesses share a link; clients record or write reviews. Video on Cloudflare Stream, data on Supabase (PostgreSQL), landing page + admin panel.
  • InstaDeck (App Store) — AI-generated flashcard decks from any topic, graded easy to hard. React Native + TypeScript.
  • GMC Scanner (Shopify App Store) — uses AI to evaluate store readiness score against Google Merchant Center requirements.
2022 — 2025
Remote
Launchify Ventures
Senior Full-Stack Engineer

US-based e-commerce reaching ~$1M/month and ~2,000 orders/day. 80–90% mobile traffic.

  • Designed and built the platform that replaced a legacy monolith — 50+ live offer funnels (blog → product → checkout → thank-you), each deployed independently with 3–5 A/B variations running in parallel, so marketing could iterate without blocking on engineering.
  • Built a shared React checkout SPA across all offers, backed by a Node.js + MongoDB API handling orders, billing, retry logic, and admin operations. JWT auth for internal users.
  • Built a React admin panel so product, marketing, and ops could configure offers, checkout flows, A/B tests, payment providers, and tracking integrations themselves — offer-launch time dropped from ~2 weeks to ~2 days.
  • Built-in analytics on both admin panels surfaced sales by offer, special-offer take rates, decline rates, and funnel breakdowns — operators could spot a failing variant within hours instead of waiting on reporting.
  • Integrated Stripe, Braintree, PayPal, Apple Pay, Google Pay. Multi-provider routing, webhook handlers, retry logic for failed orders.
  • Built server-side tracking pipelines for Facebook CAPI, Google Ads, GTM, and BigQuery — reliable event data without browser-side dependencies.
  • Manna.com — built a separate vitamin store from scratch: Next.js app with its own React admin panel and Firebase Auth customer portal. Customers could update orders, cancel, and downgrade subscriptions through self-serve flows.
  • Rebuilt a legacy subscription video platform on Next.js and migrated video delivery from AWS S3 to Cloudflare Stream — monthly infra cost dropped ~99% (~$800 → ~$5).
2020 — 2022
Remote
Launchify Ventures
Full-Stack Engineer

Joined as frontend on the legacy monolith. When the backend engineer left during COVID, learned Node.js, took over the API, and proposed the rewrite that became the modular platform above — shipped the first admin panel and offer mini-apps.

2019 — 2020
San Diego, CA
Sinlao Media
Frontend Engineer

Built an internal analytics dashboard for media buyers — Facebook ad performance and sales reporting. React, Redux, Chart.js, D3.js.

2016 — 2019
St Petersburg
IQ Option
Frontend Engineer

Built an internal monitoring dashboard at an online-trading fintech. React, Redux, real-time data over WebSockets, charts and data tables for ops teams.

03 · Toolkit

Stack

Frontend
React · Next.js · TypeScript · JavaScript
Backend
Node.js · Express · REST APIs · Webhooks · JWT · Firebase Auth · Zod
Database
MongoDB · Supabase (PostgreSQL, side projects)
Payments
Stripe · Braintree · PayPal · Apple Pay · Google Pay · Shopify
Analytics
Facebook CAPI · Google Ads · GTM · Google Analytics API · BigQuery
Infrastructure
AWS (EC2, S3, IAM) · DigitalOcean · Vercel · Railway · Cloudflare (Stream, Workers, DNS)
AI tools
Cursor · Claude · GitHub Copilot
Testing / Mobile
Playwright · Cypress · React Native (published iOS app)
04 · Background

Education

2010 — 2014
B.Sc. Computer Science
K.G. Razumovsky Moscow State University
Nov 2022
IBM Cybersecurity Analyst
Professional Certificate · Coursera
05 · Get in touch

Contact

Open to senior full-stack roles in Germany, the Netherlands, or the UK. Also open to remote roles from Spain.

Based in Madrid, Spain · Spanish Digital Nomad Visa · No EU work authorization · B2B contract / EOR · Open to relocation with sponsorship · or local-permit conversion via a Spanish employer