Costas – React Native, React, Typescript

An e-commerce platform that changes the traditional UX experience of e-shops. It simulates on-screen the experience of a mall. The content creators can organize their content in Floors, Departments, and various kinds of "virtual shelves" layouts, like ordinary shelves, displays with featured products, etc.

The customers can browse the site via a map of floors, find departments, and browse departments with a fluent UX that includes animating cards around.

• Refactored and cleaned code to become maintainable and minimize regression bugs;
• Fixed outstanding bugs;
• Eventually rewrote the whole project as it shifted in purpose and UI modernized to its current form;
• Mentored and performed code review for a team member who was working on the Dashboard part of the app.

A live e-shop for homeware where people can buy and sell stuff for home. Apart from the listing of stuff to buy based on category and the seller, users could like sellers and items, follow sellers, and chat with them.

• Worked as a senior developer in a team with a mid-level developer;
• Fixed bugs and restructured code to be easily maintainable and avoid bugs within two weeks;
• Mentored the developer and left behind some best practices in code;
• Developed an in-memory 'doc' (NoSQL docs) cache for re-use in multiple screens, which led to significantly less network traffic and list loading speeds.

A mobile app for an enterprise system that tracks the on-boarding and off-boarding of students in student buses. The app had two main parts: the "Parent" mode and the "Driver" Mode.

In "Parent" mode, parents can browse specific bus schedules and routes and declare their kids for onboarding. Then, they can follow the bus on Google Maps and receive information (and push notifications) about when and where their kids were onboarded and off-boarded.

In "Driver" mode the app works on tablets sitting next to the driver and is used as a Navigator app.

At each stop, the app switches to a list of students to be onboarded or offboarded. The process happens automatically via NFC cards. Of course, all this information is transmitted to the backend and triggers the corresponding notifications to the parents.

• Joined the project at the PoCstage and successfully delivered an MVP of a mobile part within 8 months;
• Implemented an architecture separating front-end UI and logic, enabling concurrent feature development and faster delivery;
• Established a two-phased feature development approach (e.g., building a UI prototype while the backend is in progress) for increased efficiency;
• Mentored and managed a junior developer during the building of the mobile app.

An app that allows farmers in the US to monitor and manage their center-pivot irrigation systems remotely from their phones.

The app allows one to view the status of the machinery in detail, as well as its rotation position on the field (projected on a map). It also allows to control the machinery and configure remotely its operation details (speed of turn, liquid pressure etc).

• Developed the mobile app by adding more than 30 requested features in one year;
• Fixed bugs and cleaned-up code;
• Implemented SVG graphics in an overlay on maps.