Mariia

Mariia Paik
Full-Stack Developer (Node.js / NestJS / React / Python)
Kraków, Poland | [open contact info](look above in the "contact info" section) | [open contact info](look above in the "contact info" section)
|github.com/mariiapaik | [open contact info](look above in the "contact info" section)

SUMMARY

Full-Stack Developer with 3 years of production experience building AI-powered SaaS platforms end-to-end, from
greenfield architecture to scaled features used by 200+ media buyers and digital agencies serving brands such as
Pepsi and Starbucks. Backend-leaning generalist across Node.js, NestJS, Express, and Python, with strong React
and Redux on the frontend and confident handling of MongoDB, PostgreSQL, MySQL, Redis, BullMQ, and
AWS/GCP. Shipped multiple LLM-driven features in production, including an autonomous campaign-launching
agent and a Claude-powered content-generation pipeline. Comfortable owning a feature from spec through
deployment, mentoring through code review, and working directly with product and clients.

My portfolio: https://portfolio-delta-indol-17.vercel.app/

TECHNICAL SKILLS

•​ Languages: JavaScript, TypeScript, Python
•​ Backend: Node.js, NestJS, Express, Django, REST APIs, Microservices, BullMQ, WebSockets
•​ Frontend: React, Redux, Astro, HTML, CSS, React Native
•​ Databases: PostgreSQL, MySQL, MongoDB, Redis
•​ Cloud and DevOps: AWS, GCP, Docker, CI/CD, Linux, VPS
•​ AI and Automation: OpenAI API, Anthropic Claude API, Retrieval-Augmented Generation (RAG), Vector
Databases, Prompt Engineering, n8n
•​ Integrations: Facebook Ads, TikTok Ads, Instagram, YouTube, MGID, Taboola, Outbrain, Revcontent,
Line, Tonic, Google APIs, PayPal
•​ Testing and Tools: Jest, Git, GitHub, Postman, Agile/Scrum

PROFESSIONAL EXPERIENCE

Full-Stack Developer, TrackBoost
June 2023 – May 2026 | Hybrid
AI-powered ads optimization platform for media buyers, affiliates, and digital agencies. Co-built two products
from scratch: trackboost.com (AI co-pilot for advertisers) and digital.trackboost.com (analytics and
team-management dashboard for agencies serving clients including Pepsi and Starbucks). Worked in a team of
8 full-stack engineers and 1 QA; reviewed code, collaborated directly with product and clients.
•​ Built an autonomous AI agent for affiliate marketers that takes an offer and reference and launches a full ad
campaign end-to-end: generates images and headlines via OpenAI, assembles creatives, and pushes the
campaign live to traffic sources. Replaced hours of manual creative production per buyer.
•​ Designed an LLM-based campaign optimization engine that analyzes live performance against
affiliate-marketing rules and recommends concrete actions, including budget adjustments,
pausing underperforming creatives, and generating new variations.
 •​ Built integrations with 9+ traffic sources and affiliate networks — Facebook Ads, TikTok Ads, Instagram,
YouTube, MGID, Taboola, Outbrain, Revcontent, Line, and the Tonic affiliate network — covering campaign
creation, scheduled stats collection, and unified cross-source reporting.
•​ Designed an n8n + Claude Opus content pipeline that auto-generates RSOC articles for Tonic at scale; ran in
production for several months, producing multiple campaigns per day.
•​ Shipped an AI-powered ad creative editor allowing users to generate and refine images and copy in-app,
removing dependency on external design tools.
•​ Built an influencer management system for digital agencies, including talent CRM, campaign tracking, and
reporting modules for cross-team collaboration.
•​ Built a real-time analytics dashboard with live charts aggregating data from a 70 GB MongoDB store
and multiple SQL databases across all integrated traffic sources, partner networks, and campaigns.
•​ Architected the scheduled stats-collection layer with hourly and daily jobs pulling from hundreds of
campaigns and thousands of ads across all integrated platforms, queued via BullMQ.
•​ Optimized heavy data flows: reduced load times on key dashboards from approximately 30 seconds to
near-instant, lowered database load on hot paths, and shipped continuous fixes and improvements
across the codebase.
Tech stack: React, Redux, Astro, Node.js, NestJS, Express, Python, MongoDB, PostgreSQL, MySQL, Redis, BullMQ,
Docker, AWS, GCP, OpenAI API, Claude API, n8n, Jest.

Freelance Full-Stack Developer
2024 – Present | Remote
Designed and shipped websites, booking systems, and a Telegram bot for independent clients across fitness,
wellness, and education niches. Owned the full delivery cycle from requirements gathering and design to
deployment and handover.
•​ Fitness coach booking website with service and consultation signup, contact-form lead capture, and email
notifications to the coach. Built with React and Node.js.
•​ Dance course landing and registration platform with course signup flow, built with React, Node.js,
and Astro.
•​ Podiatry clinic website with appointment booking and contact functionality.
•​ Telegram bot with PayPal integration — full payment flow plus integration with Google services.
•​ Cross-platform mobile app (side project) built with React Native and a Node.js backend.

EDUCATION

Bachelor of Science in Intelligent Systems
Technical University of Košice (TUKE), Slovakia | 2022 – 2025
Bachelor's thesis: "Integrated Development Environments for Work with Large Language Models." Designed and
implemented a Retrieval-Augmented Generation (RAG) pipeline as the core technical contribution, combining
vector-search retrieval with LLM-based generation to ground responses in a custom knowledge base.

LANGUAGES

•​ Ukrainian — Native •​ English — Upper-Intermediate (B2)
•​ Slovak — Near-fluent (C1) •​ Russian — Native