Marceli Borowczak
Poznan,Wielkopolskie
Summary
Full Stack Developer with expertise in React and AI integration. Technical Co-Founder of Zozalo — an AI-powered travel platform that transforms natural language prompts into personalized itineraries, bookings, and social experiences.
I excel at building fast, scalable web applications, incorporating AI solutions into functional products, and designing intuitive user experiences. I prioritize efficiency, quality, and user-centered design.
Overview
3
3
years of professional experience
Work History
Co-Founder & Full Stack Developer
Zozalo Technologies
03.2025 - Current
- Built and scaled Zozalo from zero to production as a full-stack engineer using Next.js 15, NestJS, and PostgreSQL
- Led the development of the AI Trip Planner, integrating OpenAI for itinerary generation with advanced prompt handling and injection protection
- Designed and implemented the Smart Booking engine for flights and hotels using the Amadeus API
- Created TripMatch™, a real-time traveler matching system using vector embeddings and social UX
- Integrated Clerk for auth, Stripe for billing, and Redis for performance optimization
- Developed a mobile-first UI with Framer Motion, Zustand, and vibe-based interactive travel pages
- Fine-tuned a custom AI destination model using QLoRA on Mistral-7B, trained on trip feedback and preference logs
- Built the full backend infra with CRON jobs, webhooks, user subscriptions, freemium point system, and analytics logging
- Launched growth and retention features like Zozalo Passport, Travel Stories, and Smart Suggestions via email/calendar integrations
Freelance Full-Stack Developer
Fiverr
06.2022 - Current
- Delivered full-stack solutions for startups and solo founders, turning product ideas into live applications
- Built responsive frontends using React, Next.js, TailwindCSS, and Framer Motion, with a focus on performance and UX
- Developed robust backend APIs with NestJS and TypeORM, including secure JWT authentication, role-based access, and admin panels
- Integrated 3rd-party APIs (Stripe, OpenAI, Amadeus, Clerk) to power payments, AI features, and auth flows
- Set up scalable infrastructure on Vercel, DigitalOcean, and Supabase, with CI/CD pipelines and production monitoring
- Worked with AI workflows: prompt engineering, embedding search, and fine-tuning (QLoRA, HuggingFace)
- Created landing pages, MVPs, dashboards, and micro-SaaS tools tailored to client business needs
- Communicated directly with non-technical founders and provided full-cycle product ownership (design → build → launch)
Frontend Developer
DevGaming.pl
06.2023 - 04.2024
- Developed and maintained React-based applications
- Implemented state management solutions with TanStack Query
- Collaborated with backend team to integrate RESTful APIs
- Optimized application performance and user experience
Education
High School Diploma -
Zespół Szkół Handlowych
PoznańHigh School Diploma -
Szkoła W Chmurze
Remote04-2024
Skills
Frontend:
Nextjs 15 React TailwindCSS Framer Motion Zustand TanStack Query
Backend:
NestJS TypeORM PostgreSQL Redis JWT Auth CRON Jobs REST APIs
AI & APIs:
OpenAI (chat/completions/embeddings) Amadeus API HuggingFace (QLoRA) Mistral-7B
Infra & DevOps:
Vercel DigitalOcean App Platform Upstash Docker GitHub Actions
Other:
Stripe Clerk Notion Figma Resend (email) i18n
Languages
English
Polish
Data Processing Consent
I, Marceli Borowczak, consent to the processing of my personal data included in this resume in accordance with Regulation (EU) 2016/679 of the European Parliament and of the Council (GDPR) for the purposes of the current recruitment process.
Timeline
Co-Founder & Full Stack Developer
Zozalo Technologies
03.2025 - Current
Frontend Developer
DevGaming.pl
06.2023 - 04.2024
Freelance Full-Stack Developer
Fiverr
06.2022 - Current
High School Diploma -
Zespół Szkół Handlowych
High School Diploma -
Szkoła W Chmurze
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