Hey,
My name is Seraphim Sakiewicz

I build things for the web

About Me

Full‑Stack engineer specializing in React, Node, TypeScript, and AWS (Lambda, DynamoDB, OpenSearch, StateMachines).

Currently building Hack Frontend, a platform dedicated to enhancing frontend development skills and preparing candidates for successful interviews.

Over 3 years of experience in the industry and I have built applications for the insurance, environmental sustainability, and financial industries.

Sparta, New Jersey

January 2025 - Present

Managed database migrations using Prisma and Neon.js for seamless schema updates and efficient data handling.
Led the UX/UI design planning for pagination and filtering of our problems, to allow users to find and share them easily.
Implemented dynamic URL‑based filtering and responsive pagination using Next.js, Radix UI, and Lucide React.
Built a promo code system using React Hooks (useState, useEffect) to boost user engagement and platform growth.

Sparta, New Jersey

July 2023 - December 2024

Built a full-stack AWS S3 content management system with React and Node.js, empowering the marketing team to manage their content independently.
Rebuilt over 100 pages from jQuery to modern, responsive pages using React, TypeScript, and Material-UI (MUI), and tested thoroughly with React Testing Library for maintainability and performance.
Developed engaging, interactive tools such as quizzes and calculators with React Reducer, leveraging MUI's pre-built components and responsive design system.
Conducted rigorous code reviews, promoted best practices, and optimized GitLab deployments to foster continuous improvement and ensure high-quality code.

Marsa, Malta

March 2022 - July 2023

Developed a Node.js/Express server hosted on AWS Lambda to seamlessly integrate Xero and Sage accounting APIs, enabling customers to import invoices and track their carbon usage.
Implemented an AWS Step Function to efficiently calculate carbon usage by importing invoices through a well-architected state machine.
Built a robust and user-friendly Admin Portal using React with TypeScript, empowering admins to efficiently assist customers and manage user permissions and their data.
Significantly enhanced the efficiency and reliability of the CRM application by implementing comprehensive automated testing using Cypress for end-to-end tests and Jest for unit tests.
Provided mentorship and guidance to two junior programmers, focusing on best practices and conducting thorough code reviews to ensure high-quality contributions.

Moscow, Russia

May 2021 - May 2022

Developed complex SQL queries and stored procedures for the Node.js backend, optimizing data retrieval and ensuring secure access based on user roles.
Built a dynamic AdInsure Insurance platform using React, integrating UI components to create a seamless user experience.
Utilized Node.js and Puppeteer to generate dynamic contracts based on user input, streamlining the contract creation process.
Implemented validation handling for the contract creation process, ensuring data integrity and minimizing potential errors.
Designed and executed unit tests using Mocha, guaranteeing the stability and reliability of new features.