Senior Software Developer

Sergiu Uifalean

I build fast, scalable things for the web —
and occasionally convince AI to think it came up with the idea.

React & Next.js Vue.js GraphQL AI Integration
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About

Software developer with 8+ years shipping products that millions of people actually use. I care about craft — fast interfaces, clean abstractions, and that rare feeling when everything just works. Recently deep into real-time systems and AI integration.

From Romania to the Netherlands to Denmark — I've built EdTech platforms, invoice automation SaaS, e-commerce engines, and business-process tools across three countries.

8+ Years Experience
3 Companies
3 Countries
Expertise

What I bring

React & Next.js

Deep expertise across both — from real-time chat UIs to large-scale migrations, performance tuning, and complex state management.

Vue.js & GraphQL

Built high-traffic Shopify storefronts with Vue and Apollo GraphQL — theme architecture, performance tuning, and seamless storefront API integration.

AI Integration

From LLM-powered product features to AI-assisted code review, CI/CD automation, rapid prototyping, and data-driven feature validation.

Frontend

  • Next.js
  • Vue.js
  • Angular
  • Shopify Liquid
  • Tailwind
  • SCSS
  • GraphQL
  • Playwright

Backend & Data

  • .NET Core
  • Node.js
  • PHP Laravel
  • SQL Server
  • MongoDB
  • Redis
  • AWS Lambda
  • Sanity

DevOps & Tooling

  • Docker
  • Kubernetes
  • GitHub Actions
  • Jenkins
  • Helm
  • AWS
  • Shopify

AI & Real-time

  • OpenAI API
  • Cursor
  • Gemini
  • Amazon Translate
  • Embeddings
  • WebSockets
  • MQTT
  • SSE

Analytics

  • PostHog
  • Google Analytics
  • GTM
  • Meta Pixel
  • A/B Testing
  • UserCentrics
Career

Where I've been

Hobbii 2024 — Present

Senior Software Developer

  • Led the front-end team on a high-traffic e-commerce platform — owned Shopify theme architecture, CI/CD, E2E testing, and analytics across multiple domains.
  • Standardised the entire tracking stack (PostHog, GA4, GTM, Meta Pixel) with GDPR-compliant consent management, cutting tracking dev time by 90%.
  • Drove the Shopify migration from OpenCart end-to-end — coordinating across AWS, custom Shopify apps, identity management, and back-end services.
  • Leveraged LLMs for rapid prototyping and data-driven feature validation through A/B testing with proper guardrails.
Studocu 2022 — 2024

Senior Software Developer

  • Architected and shipped the real-time chat feature — WebSockets, MQTT, SSE — and integrated LLM-powered tools into the product.
  • Led the Next.js migration effort, optimising builds, pipelines, and dependency management across teams.
  • Created technical roadmaps, authored RFCs and ADRs, and drove front-end guild standards for millions of monthly users.
Yonder 2019 — 2022

Senior Developer & Tech Lead

  • Led the front-end on an invoice-automation SaaS — Angular migration, Web Components, design system, and CI/CD with Docker & Kubernetes.
  • Bridged business and engineering: planned roadmaps, mentored junior devs, and made long-term architecture decisions.
Yonder 2016 — 2019

Web Developer

  • Built a business-process platform with MeteorJS & React — generic, future-proof modules used in ways that surprised even us.
  • Introduced linting, coding conventions, and functional programming patterns that raised code quality across the team.
Get in Touch

Let's build
something.

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Yes, an AI helped me build this site. No, it can't replace me. I asked.