
Jakub
From Poland (UTC+2)
5 years of commercial experience
Lemon.io stats
5
projects done1606
hours worked1
offers now 🔥Jakub – React, React Native, Node.js
With 5 years of experience under his belt, Jakub has a deep understanding of Javascript/Typescript and its various libraries and frameworks. He's a Senior front-end/mobile developer whose strengths lie in his exceptional knowledge of React, React Native and a great acquaintance with Node.js. He holds a Bachelor's degree in Computer Science and has proven himself to be an excellent communicator in both technical and non-technical English.
Jakub also has hands-on experience integrating AI tools, including OpenAI and Anthropic chat models. If you're looking for a developer who can deliver exceptional results, Jakub is your man!
Main technologies
Additional skills
Testimonials
Direct hire
Potentially possibleReady to get matched with vetted developers fast?
Let’s get started today!Experience Highlights
Tech Lead
Telegram bot that scrapes news about new listings on popular exchanges and allow users to instantly trade on connected exchanges
- Created Telegram bot interface;
- Integrated with Bybit, Binance, Gate.io, and MEXC;
- Created a system that scrapes listings from all popular exchanges;
- Created an AI assistant that analyzes tokens and gives advice for bot users.
Senior Front-end Developer
One of the largest ferry ticketing companies.
- Developed pixel-perfect, responsive UI components based on Figma designs;
- Refactored and modernized the legacy codebase to integrate newly built components;
- Actively contributed to discussions and decisions regarding frontend architecture and best practices.
Blockchain Engineer
This is an all-in-one decentralized finance hub. From creating liquidity pools to accessing smart dashboards, the app helps users identify the best yields, optimize their portfolio, and automate transactions, all backed by T-Bill yields.
- Integrated with UniswapV4 protocol (Liquidity Pool creation);
- Audited TokenFactory smart contract;
- Built front-end for Liquidity Pool creation;
- Integrated with Uniswap's subgraph;
- Created a staking smart contract.
Full-stack Developer
A Web3 project featuring an AI-driven interview process. Users underwent three evaluation stages: Twitter profile analysis, a knowledge test, and an AI-conducted interview. The process concluded with a performance report and score.
- Created front-end and back-end architecture;
- Deployed the project infrastructure and services on AWS;
- Built a custom reporting system from scratch, tailored to business needs;
- Integrated Anthropic AI models to enhance product capabilities;
- Developed a unique, automated interviewing pipeline to streamline candidate evaluation.
Front-end Team Lead
The project is about creating one of the first AI-related NFT collections in the company's game universe.
- Led the front-end team, overseeing the development;
- Delivered an innovative solution integrating Web3 technologies with AI capabilities.
Senior Javascript Developer
One of the most important freight exchanges in Europe, which offers a modern logistics platform for road transport. The platform brings together shipping companies, logistics operators, forwarders, and carriers.
- Facilitated the migration from an outdated Leaflet map system to a modern, scalable Mapbox solution;
- Maintained and optimized legacy code built on a custom framework, ensuring stability and performance.
Senior React Native Developer
It is a company that specializes in developing apps for charity organizations, football teams, parishes, etc. The app comprises essential social platform elements and allows companies to raise money for goals and events. The project was fascinating as over 50 apps shared the same React native codebase.
- Updated and refactored 4-year-old social modules, leveraging React hooks and context for improved performance and maintainability;
- Debugged and resolved multiple critical bugs to ensure a seamless user experience;
- Developed over 10 new variants of the app, expanding its functionality and adaptability;
- Introduced Jira for project management and implemented Sprint releases, transitioning from Redmine;
- Created comprehensive API documentation, addressing the previous lack of documentation and improving team collaboration.
Front-end Developer
This is one of the UK's most innovative blockchain-related start-ups. Its goal is to simplify and accelerate the mortgage process. It consists of multiple apps that a typical broker would use into one well-designed app.
- Refactored and redesigned the mortgage sourcing app;
- Implemented document signing functionality;
- Builta mortgage affordability app based on webscraping;
- Wrote unit tests for each functionality;
- Built reusable components in the shared library.
Front-end Developer
This is a Polish fintech company that sends money from the UK to Poland. Apps allow clients to manage accounts and send money with different transfer types.
- Developed secure applications for safe money transfers;
- Designed intuitive mockups in Figma, ensuring a user-friendly interface;
- Collaborated with project managers to define and optimize UX workflows;
- Proposed and implemented a modern front-end architecture to enhance scalability and performance.
Full-stack Developer
This is one of the biggest Polish CRM. They decided to make a side-project that consisted of creating a 'buy now pay 30 days later' form that could be integrated into e-commerce sites.
- Maintained the old version of the solution;
- Implemented and deployed new architecture to simplify the deployment process;
- Implemented kontomatik integration;
- Wrote tests for the new frontend architecture;
- Created CI/CD scripts.
Tech Lead / React Native Developer
This is a Polish electronic shop and e-commerce company. They wanted to deploy an app that would allow them to engage with their customers.
- Created a native login form and enabled biometric login;
- Worked on advanced JavaScript code that allowed the website to communicate with the native app;
- Created a push notifications system with a simple CRM.
Team Lead / React Native Developer
The project's goal was to create an app that contains a blog, 2D games, social competitions, and photo editing capabilities. It gives the company a social platform to host events and connect to customers. The app was developed in React Native, which allowed swift project delivery due to the nature of the cross-platform technology.
- Split tasks between two other members of his team;
- Deployed the app on the Google Play Store and the App Store;
- Convinced the client to use Expo SDK to provide on-air updates in a testing environment;
- Implemented push notifications with a simple CRM;
- Created integration with WordPress blog API (fetching categories, tags, displaying blog pages inside the app);
- Developed a photo editing module, featuring filters and stickers, to enhance user creativity;
- Crested 2 different 2d games (memory and "czółko").