Bogdan B.
Senior Full Stack Engineer
Experience
Mar 2022 - Present
3 years 9 monthsWarsaw, Poland
Senior Full Stack Engineer
Makolab
- Led development of a global SaaS platform using React (Next.js) on the frontend and Python (FastAPI) and Node.js (Express.js) on the backend.
- Designed and implemented REST and GraphQL APIs for catalog, checkout, analytics, and user modules, optimized with PostgreSQL and Redis caching.
- Delivered responsive and accessible React UIs with Tailwind CSS, Storybook, and reusable component libraries.
- optimized performance with server-side rendering (SSR), code-splitting, and lazy loading, cutting LCP by 35% and improving CoreWeb Vitals.
- Integrated Stripe and PayPal payments, applying JWT/OAuth2 authentication and PCI-DSS compliance best practices.
- Built background workers and async job queues with Celery and Redis for invoice generation, email notifications, and third-party data synchronization.
- Delivered an AI-powered product search & recommendation system using LangChain and Pinecone, improving product discovery accuracy.
- Developed an internal documentation Q&A assistant using OpenAI and FastAPI to support employees with instant knowledge retrieval.
- Prototyped multi-agent workflows (customer support bot and analytics bot) with LangGraph, enabling automated triage and reporting.
- Established CI/CD pipelines with Docker and GitHub Actions, automated deployments to AWS EC2 and AWS Lambda with CloudFront for CDN.
- Configured monitoring and alerting with Prometheus, AWS CloudWatch, and structured logging for backend observability.
- Migrated services toward microservice architecture, decoupling catalog, checkout, and analytics for easier scaling.
- Led architecture review sessions and coached junior developers, raising team delivery velocity and reducing bug count in production.
- Collaborated closely with design and product teams to align technical solutions with business goals, ensuring rapid but stable releases.
Jul 2019 - Feb 2022
2 years 8 monthsWarsaw, Poland
Full-Stack Engineer
IXOPAY
- Built core services for a payment orchestration platform with Python (Django) on backend and React on frontend.
- Designed role-based dashboards and reporting tools with React, Redux, and Material UI.
- Integrated real-time fraud monitoring with anomaly detection and WebSockets for live transaction status updates.
- Developed middleware and webhook processors in Django Rest Framework to handle high-volume partner API traffic.
- Strengthened security with OAuth2 flows, token expiration, and rate limiting.
- Prototyped an AI-based risk scoring engine using Hugging Face Transformers, applied for fraud prevention.
- Automated testing with Pytest (backend) and Cypress (frontend), integrated coverage into CI pipelines for release confidence.
- Partnered with compliance teams to ensure PCI DSS and GDPR readiness.
Oct 2015 - Jun 2019
3 years 9 monthsDelft, Netherlands
Web Developer
Fabrique
- Delivered editorial tools and CMS features with React and Symfony.
- Migrated legacy jQuery applications into modern React and Redux modules, improving maintainability.
- Partnered with backend engineers to design and consume REST APIs for dynamic user interfaces.
- Focused on WCAG 2.0 accessibility compliance, tested with Lighthouse and screen readers.
- Optimized frontend pipelines with Webpack and Vite, cutting bundle sizes and improving build speed.
Summary
Senior Full-Stack Developer with 10+ years of experience building scalable SaaS, eCommerce, and AI-powered platforms. Specialized in Python (FastAPI, Django) and React, with solid experience in Node.js and modern AI/LLM systems. Skilled at designing cloud-native architectures, secure APIs, and performant frontends. Recently focused on integrating AI agents, semantic search, and vector databases into production systems. Strong track record of mentoring teams, improving CI/CD pipelines, and leading architecture discussions to deliver high-impact software in agile environments.
Languages
English
AdvancedDutch
ElementaryPolish
ElementaryEducation
Sep 2012 - Jul 2015
Delft University of Technology
Bachelor of Computer Science · Computer Science · Delft, Netherlands
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