Gergely Újvári

A Node.js-based app using the Apollo GraphQL architecture was brand new then. I was one of the two architects and a senior full-stack developer handling the design of the GraphQL scheme with the database integration, the notification system, and the Google Map integration to visually show the network topology and errors. Used multiple integrations to enrich the map experience, including weather warnings, planned maintenance, and positions of repair vehicles. We also used the Meteor framework with TypeScript, React with Redux for the front end, and Redis for notifications.

The application was built for a large electric utility company, has several hundred active users, and monitors the electricity in two-thirds of the country.

I developed a marketplace component into the web application for video annotation jobs. Each job had a defined task needs to be done and a reward for doing those. Individual agents can pick the jobs, and another group can review them. Each of these jobs had a complicated lifecycle (with automatic and manual steps, calling outside services, error states, permissions, and money handling), so it had to be robust and easily adaptable for future changes.

I created a small package to efficiently define finite-state machines and state transitions to achieve this. It became the controller both for the UI and for the server-side to allow/disallow actions and display data based on the state of a job.

Also, UI tools were created to auto-generate the state-transition graph for the whole job process and show a step-by-step progress bar for a job, for example.

I needed to rebuild a video library from scratch, but with a modular architecture, interchangeable components, and rich configuration options (which can be set by the clients).

The library needed to be inserted into any webpage by a simple HTML snippet. So a loading stub was created, and it only needed a client ID to work.

The library itself was built by modules. A module had configuration options (described in a JSON file) and dependencies to other modules. These configuration files were the single sources of truth. Based on them, the configuration UI page (with forms) was auto-generated, and the module dependency was calculated not to load any unused modules.

The clients could configure if they wanted to embed a single video or a full library, maybe with filters. Both iframe and non-iframe embeds were available. Themes were also introduced.