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I am a Senior Software Engineer with 11+ years of experience building web and data-driven systems, plus scalable cloud architectures across Azure, AWS, and GCP. I specialize in Python (FastAPI, Django), React/TypeScript, and PostgreSQL, delivering robust backend services, API optimization, and production-grade ML/data pipelines. I thrive on clean, efficient code and collaborative agile workflows, enjoy mentoring teammates, and love turning complex problems into scalable, maintainable solutions.…I am a Senior Software Engineer with 11+ years of experience building web and data-driven systems, plus scalable cloud architectures across Azure, AWS, and GCP. I specialize in Python (FastAPI, Django), React/TypeScript, and PostgreSQL, delivering robust backend services, API optimization, and production-grade ML/data pipelines. I thrive on clean, efficient code and collaborative agile workflows, enjoy mentoring teammates, and love turning complex problems into scalable, maintainable solutions.

Jakub Zielinski

Full Stack Developer, Developer, Back-End Developer, +4

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I am a Senior Software Engineer with 11+ years of experience building web and data-driven systems, plus scalable cloud architectures across Azure, AWS, and GCP. I specialize in Python (FastAPI, Django), React/TypeScript, and PostgreSQL, delivering robust backend services, API optimization, and production-grade ML/data pipelines. I thrive on clean, efficient code and collaborative agile workflows, enjoy mentoring teammates, and love turning complex problems into scalable, maintainable solutions.…I am a Senior Software Engineer with 11+ years of experience building web and data-driven systems, plus scalable cloud architectures across Azure, AWS, and GCP. I specialize in Python (FastAPI, Django), React/TypeScript, and PostgreSQL, delivering robust backend services, API optimization, and production-grade ML/data pipelines. I thrive on clean, efficient code and collaborative agile workflows, enjoy mentoring teammates, and love turning complex problems into scalable, maintainable solutions.

Available to hire

I am a Senior Software Engineer with 11+ years of experience building web and data-driven systems, plus scalable cloud architectures across Azure, AWS, and GCP. I specialize in Python (FastAPI, Django), React/TypeScript, and PostgreSQL, delivering robust backend services, API optimization, and production-grade ML/data pipelines.

I thrive on clean, efficient code and collaborative agile workflows, enjoy mentoring teammates, and love turning complex problems into scalable, maintainable solutions.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

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Expert

Expert

Expert

Expert

Expert

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Expert

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Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Work Experience

Senior Software Engineer at The Brain Software House

January 1, 2022 - Present

Delivered Angular based front-end UX/UI for Global Content Service, converting Figma designs into reusable components, improving development speed by 30%. Developed GraphQL Apollo service using Node/Express and KPI dashboards API, increasing data query efficiency by 40% and enabling clearer business insights. Optimized API response time by 50% through MongoDB query tuning and Redis caching; containerized applications with Docker for streamlined deployment. Automated testing with Jest and Cypress, reducing bugs in production by 35% and improving overall software quality. Managed AWS deployment and CI/CD pipelines using Jenkins, achieving 99.9% uptime and cutting deployment time by 60%.

Full Stack developer at SolutionLab

December 31, 2021 - July 28, 2025

Architected RESTful APIs with Nest.js, implementing secure CRUD operations and authentication that supported 10k+ daily active users. Designed scalable multi-tenant SaaS e-commerce Node backend platform with tenant isolation, subscription management, and multi-currency support, boosting client retention by 25%. Engineered ETL pipelines with cron jobs and custom scrapers, automating data updates and increasing accuracy by 98%. Activated OpenAI’s API for real-time product description generation, cutting content creation time by 60% and freeing up the marketing team's bandwidth to focus on strategy. Established Sentry monitoring and custom alerting, reducing average bug resolution time by 45%.

Mid-Full Stack Developer at Merch Informer

May 31, 2019 - July 28, 2025

Built PHP/Laravel web applications, improving site performance by 35% and user satisfaction scores. Created Angular dashboards with Chart.js and DataTables, improving data visualization clarity and user productivity by 30%. Delivered Chrome extension including multi-product pricing and design export features, increasing extension usage by 15%. Deployed all projects on AWS EC2 and RDS, achieving 99.8% uptime and responsive client support. Integrated Stripe payment and subscription logic, boosting successful transactions by 40%.

Front End developer at Dotsquares

February 28, 2017 - July 28, 2025

Created React/Redux UI components and booking system, improving appointment scheduling efficiency by 50%. Implemented unit tests with Jest and Mocha, increasing frontend reliability and reducing defects by 30%. Revamped legacy WordPress themes with React components, enabling interactive user interfaces and expanded the functionality of 15+ existing website features to increase user engagement. Introduced Storybook for isolated component development, improving UI consistency and reducing design bugs by 25%. Enhanced SEO through structured content and optimized URLs, increasing organic traffic by 18%.

Senior Software Engineer at The Brain Software House

January 1, 2022 - Present

Designed, developed, and deployed scalable FastAPI and Django REST microservices powering ML-driven recommendation systems and analytics. Created PostgreSQL schemas, optimized queries and indexes to boost performance and scalability. Implemented unit, integration, and performance tests with Pytest, Postman, and Locust, increasing backend test coverage to 95%. Built React/TypeScript dashboards with reusable components and data visualizations via Chart.js and Recharts. Automated CI/CD pipelines using Jenkins, Docker, and Kubernetes to improve deployment consistency and rollback safety. Introduced API contract testing and schema validation with Pydantic and OpenAPI to ensure stable service integration. Deployed applications on Azure Databricks and AWS EC2/EKS, and managed production observability with Prometheus and Grafana. Implemented RBAC authentication, JWT-based auth, and OWASP security practices.

Full Stack Developer at SolutionLab

December 1, 2021 - October 24, 2025

Engineered high-performance FastAPI and Node.js APIs with async I/O, middleware, and authentication layers (JWT/OAuth2). Designed PostgreSQL data models, views, and migration strategies with Alembic and SQLAlchemy ORM. Developed full-featured React/Next.js applications with TypeScript, React Query, and Redux Toolkit, improving DX and runtime stability. Implemented end-to-end tests using Cypress, Jest, and Pytest, reducing production regressions by 40%. Created mock servers and Postman collections for API testing and contract validation. Automated builds and deployments using GitHub Actions, Docker Compose, and AWS ECS, ensuring seamless continuous delivery. Deployed centralized logging and error tracing via Sentry and Elastic Stack, enhancing observability and incident response. Conducted code reviews, enforced PEP8 standards, and mentored junior developers on testing and architectural best practices.

Mid Full Stack Developer at Merch Informer

May 1, 2019 - October 24, 2025

Built Laravel and Node.js backend services transitioning toward microservice architecture for scalability. Created and consumed RESTful APIs with Postman and Insomnia, integrating third-party systems (Stripe, Amazon MWS). Implemented React dashboards and data-driven interfaces with Redux. Established automated test suites using PHPUnit, Mocha, and Jest, reducing release bugs by 35%. Optimized PostgreSQL/MySQL queries and applied Redis caching, improving API latency and throughput. Managed AWS EC2, S3, and RDS infrastructure, automating deployment pipelines with Terraform. Created CI/CD pipelines integrating testing, linting, and container builds for consistent code quality. Introduced Dockerized local environments to standardize dev/test setups across teams.

Front-End Developer at Dotsquares

February 1, 2017 - October 24, 2025

Developed React/Redux UI components and booking systems integrated with REST APIs. Implemented comprehensive testing using Jest, Mocha, and React Testing Library, achieving 90% component coverage. Built Storybook-based design system ensuring UI consistency across multiple projects. Integrated automated CI pipelines with Git and Jenkins, triggering build and test workflows for every commit. Used Lighthouse and Cypress to test performance, accessibility, and end-user flow. Migrated legacy WordPress and AngularJS codebases to React, enabling better modularity and reusability. Optimized SEO and analytics tracking, increasing organic reach by 18%.