
David Szakacs
Verified Expert in Engineering
Software Developer
Cluj-Napoca, Cluj County, Romania
Toptal member since April 13, 2022
David has several years of experience developing web and hybrid applications using Vanilla JS, Angular, React, and Electron. He has developed his communication skills by collaborating directly with his clients and mentoring other developers. David has led small teams and directed product efforts, continuously striving to innovate work processes and code standards.
Portfolio
Experience
- JavaScript - 8 years
- Node.js - 7 years
- TypeScript - 7 years
- React - 6 years
- Python - 6 years
- HTML5 - 6 years
- CSS3 - 6 years
- Angular - 3 years
Preferred Environment
JetBrains IDE, WebStorm, Visual Studio Code (VS Code), Windows, MacOS, Linux, n8n, Azure, Docker
The most amazing...
...product I've developed is a fully automated price comparison and computer configuration platform that ranked as the top product in its category in Romania.
Work Experience
Technical Co-founder
Routena
- Architected a multi-tenant transport management platform from scratch using NestJS, React, and React Native—spanning 40+ back-end modules, and 25 feature domains—with tenant isolation, RBAC, and Stripe SaaS billing.
- Created a real-time GPS fleet tracking system integrating tens of telematics providers via scheduled polling with gRPC live updates, combined with TomTom/Google Maps and proprietary routing for per-country distances, toll costs, and fuel estimates.
- Built an AI-powered document processing pipeline using OpenAI and Google Gemini that extracts structured order data from uploaded PDF transport orders and auto-matches entities against the customer database.
- Designed a full invoicing and e-invoicing platform supporting multi-currency accounting with automated exchange rate caching, customizable PDF templates, and integration with Romania's system for legally compliant electronic invoice submission.
- Integrated Twilio Voice SDK to enable real-time inbound and outbound calling from the web app, featuring browser-based WebRTC calls, intelligent routing to online users, live call transfers, and voicemail recording with transcription.
UX Engineering Lead
Microsoft
- Took multiple incubation projects within Azure Core from the idea stage to MVP and helped them find product-market fit before handing them over to other teams for maintenance and scaling.
- Implemented comprehensive testing systems and pipelines for front-end web applications, covering everything from unit, integration, and E2E tests to visual regression, performance regression, and UX flow efficiency testing using AI.
- Developed reusable components and boilerplate applications that integrate AI into web applications to enhance the user experience.
Full-stack Developer
PC Builder
- Developed a platform for tracking and aggregating thousands of products in the computer segment from several online retailers.
- Created value for users by automatically generating the best hardware configurations for their needs.
- Oversaw and co-collaborated on the planning, development, marketing, DevOps in Azure, data gathering, and processing pipelines and bots from start to present.
- Analyzed the performance of new features and implemented solutions to improve them.
Full-stack Developer
Freelance
- Implemented web applications from scratch for small and mid-sized businesses.
- Implemented automated solutions for manual processes for businesses to reduce the workload and prevent mistakes.
- Integrated third-party services and components into existing web applications.
Experience
Arlopass | AI Wallet Browser Extension
https://arlopass.com1. A canonical wire protocol with version negotiation and capability scoping
2. A Chrome Manifest V3 extension with consent-gated approval flows
3. A local bridge daemon handling HMAC handshake auth, session keys, anti-replay nonces, and default-deny policy evaluation
4. A pluggable adapter runtime with Ed25519-signed manifests for providers like Ollama, OpenAI, Claude, and Gemini; and React bindings plus a Vercel AI SDK transport layer for seamless framework integration and more.
Key contributions include the dual-enforcement security model (extension preflight and authoritative bridge gate), the signed policy bundle system for enterprise governance, privacy-preserving audit logging with JSONL/OTLP export, and the end-to-end streaming protocol design.
Excalimate | Web-based Video Animation Studio
https://excalimate.comscale, rotation, draw-on effects), a timeline UI with per-element tracks and interpolation curves, and an export pipeline using WebCodecs for MP4/WebM, gif.js for GIFs, and programmatic SVG animation.
A standout feature is the MCP server—a Node.js/Express service with 23 tools that enable AI agents (GitHub Copilot, Claude, and Cursor) to create and animate diagrams programmatically, with a real-time live preview via SSE. I also authored 16 AI skill definitions that dramatically improve output quality for specific diagram types.
Sharing uses end-to-end AES-256-GCM encryption via the Web Crypto API—the server never sees the key. Deployed on Cloudflare Pages/Workers/R2.
STACK
React 19, TypeScript, Zustand, Mantine 8, Tailwind CSS, Excalidraw, Vite, Cloudflare
Frontester
Sapviz
Education
Bachelor's Degree in Computer Science
University of Sapientia - Targu Mures, Romania
Skills
Libraries/APIs
Node.js, React, Chart.js, Stripe API, Mantine, Puppeteer, D3.js, Google Maps API, WebRTC, Pandas, Leaflet
Tools
n8n, Notion API, Notion, Prisma, WebStorm, PyCharm, DataGrip, GIS, Web GIS, TomTom, Excalidraw, NPM
Languages
JavaScript, Python, TypeScript, CSS, HTML, HTML5, CSS3, PHP, C#.NET, Python 3, SCSS, C#, SQL, Java, Kotlin
Frameworks
Next.js, Tailwind CSS, NestJS, Angular, Scrapy, Electron, Selenium, .NET 5, Material UI, .NET, React Native, gRPC, Symfony, Laravel
Storage
JSON, PostgreSQL, MongoDB, MySQL, Oracle SQL, Redis
Paradigms
REST, Agile, Azure DevOps, Management, Model Context Protocol (MCP)
Platforms
Visual Studio Code (VS Code), Windows, Linux, Azure, Twilio, WordPress, Shopify, MacOS, Android, Docker, Mapbox
Other
Architecture, Front-end, Full-stack, APIs, Supabase, Tailwind UI, Startups, Web Scraping, Webhooks, RESTFul APIs, User Interface (UI), TanStack, Data Extraction, Document Processing, Full-stack Development, Web App Development, PDF, Back-end, MVP Design, Data Visualization, Large Language Models (LLMs), Generative Artificial Intelligence (GenAI), Design, OpenAI, AI Agents, Artificial Intelligence (AI), Prompt Engineering, API Integration, Customer Relationship Management (CRM), WebSockets, Maps, Vehicle Routing, CRM, TMS, Gemini, Anthropic, Zustand, Vite, Cloudflare, Web Extensions
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