Marcin N.
Senior Full-Stack Engineer
Experience
Jan 2023 - Present
2 years 11 monthsSenior Full-Stack Engineer
Cegeka
- Worked on a SaaS healthcare platform optimizing patient data analytics and secure teleconsultation.
- Led full-stack feature delivery and system optimization using React, Next.js, and Node.js.
- Developed modular React components and implemented Next.js 13 App Router architecture for dynamic routing, enhancing UI performance and accessibility compliance.
- Designed a micro-frontend strategy integrated with shared libraries using Webpack Module Federation to support multiple product teams with minimal build coupling.
- Built backend modules in Node.js and Express, implementing efficient API caching layers via Redis and request tracing with OpenTelemetry and Grafana Tempo.
- Integrated healthcare data pipelines with FHIR-compliant APIs, ensuring HIPAA alignment and encryption standards using AWS KMS and Lambda.
- Introduced AI embedding services with OpenAI API and TensorFlow.js for medical image metadata tagging and contextual search.
- Refined build automation using Nx monorepo, Vite, and TypeScript, reducing build overhead and improving DX (developer experience).
- Developed real-time dashboards with Socket.IO and D3.js visualizations for clinical monitoring.
- Integrated Cypress, Jest, and React Testing Library for comprehensive E2E and unit testing pipelines.
- Collaborated closely with data science and backend teams, improving API latency through optimized GraphQL resolvers and PostgreSQL indexing strategies.
- Migrated legacy code from class components to React Hooks and Context API, improving readability and maintainability.
- Conducted internal workshops on clean architecture, TypeScript generics, and React performance profiling using React Profiler and Web Vitals.
- Led and mentored 5 engineers, reviewing PRs, driving code standards, and aligning engineering decisions with product vision.
Mar 2021 - Dec 2022
1 year 10 monthsFull-Stack Engineer
qurix Technology GmbH
- Contributed to a microservice-based video analytics platform combining real-time data processing and AI recommendation engines.
- Focused on backend scalability and intelligent client-side performance.
- Architected core backend using Node.js, NestJS, and TypeORM, implementing event-driven design via Kafka and RabbitMQ to handle asynchronous media workloads.
- Created React dashboards for analytics visualization using Recharts and React Query, focusing on concurrent state updates and streaming performance.
- Integrated AI embedding pipelines using SentenceTransformers and PyTorch for recommendation and content-based retrieval features.
- Containerized services with Docker and orchestrated using Kubernetes, defining microservice deployment patterns optimized for autoscaling workloads.
- Applied JWT + OAuth2 authentication with Auth0, enhancing security while ensuring seamless cross-service authorization.
- Refined API gateway layer using GraphQL Apollo Federation, improving endpoint composition and schema visibility.
- Leveraged ElasticSearch for metadata indexing and search relevance scoring, enabling near-instant retrieval of tagged media.
- Automated CI/CD using GitHub Actions, SonarQube, and Jira workflows integrated with Slack for real-time deployment notifications.
- Collaborated with cross-functional engineers to define monitoring metrics using Prometheus and Loki for distributed tracing.
Apr 2016 - Dec 2020
4 years 9 monthsSoftware Engineer
Microsoft Consulting Services
- Worked across internal and partner-facing projects within the Microsoft Consulting Services group, focusing on enterprise app modernization and secure web application delivery.
- Developed enterprise front-end portals using React, TypeScript, and Azure Functions, integrating Cosmos DB and Azure API Management for scalability.
- Assisted in migration of legacy ASP.NET MVC apps to React/Node.js hybrid architecture, optimizing load times via CDN caching and Service Workers.
- Enhanced CI/CD using Azure DevOps Pipelines, implementing gated check-ins and release automation scripts.
- Contributed to internal ML data labeling tool using Python (Flask) and TensorFlow Serving APIs for internal model evaluation.
- Participated in code reviews and sprint retrospectives, emphasizing code clarity and test coverage.
Oct 2014 - Mar 2016
1 year 6 monthsSoftware Developer
Saga Group
- Built and maintained web interfaces and internal CMS systems using Java, C++, HTML5, CSS3, and JavaScript for insurance and operations teams.
- Created responsive layouts and dynamic tables using Bootstrap, jQuery, and Ajax for faster data interaction.
- Integrated backend logic in Java Servlets and optimized I/O performance by introducing connection pooling and caching strategies.
- Maintained legacy C++ modules for data ingestion and coordinated with QA to verify build stability.
Summary
Full-stack engineer skilled in React, Next.js, and Node.js, with deep experience in designing scalable web systems, API architecture, and microservices. Adept in integrating AI-powered workflows and embedding models into SaaS solutions. Strong in cross-team collaboration, technical communication, and mentoring. Passionate about performance tuning, developer tooling, and delivering clean, maintainable systems within agile environments.
Languages
English
AdvancedEducation
Oct 2013 - Jun 2014
Imperial College London
Master of Science · Computer Science · London, United Kingdom
Oct 2010 - Jun 2013
Imperial College London
Bachelor of Science · Computer Science · London, United Kingdom
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