I worked mainly on open source side projects such as:

Sandglass https://github.com/celrenheit/sandglass a distributed, horizontally scalable, persistent, time ordered message queue. It was developed to support asynchronous tasks and message scheduling which makes it suitable for usage as a task queue.

Sandflake https://github.com/celrenheit/sandflake decentralized, sequential, lexicographically sortable unique id.