Slick Plus

Slick Plus (Slick+) is a platform designed to enhance knowledge sharing and collaboration in hybrid work environments. It focuses on creating, sharing, and learning through bite-sized videos, which helps in onboarding, mentoring, and upskilling employees.

I joined in 2024, shortly after our CTO when the product was being made available to its early testers. Together, we created the dev and production environments added testing frameworks and created an aws CDK and CI configuration to run tests and deploys to the environments.

I operated in all facets of the project, from implementing UI from figma draw ups to creating and testing the API in the backend to coming up with and writing the AWS infraestructure. The project is built with Angular in the front, Nestjs running in the a k8s cluster and I mostly enjoy the familiarity.

Challenges

Slow loading videos

Being a sort of streaming platform brought new challenges related to video processing I had to tackle. Firstly, videos that were recorded in the browser were not seekable in Chrome. There is an old issue that was marked as won't solve about this very problem. The workaround is to use Node-EBML which writes the appropriate time markers to the video file, making it playable. Still, this was not enough. I noticed that, depending on the video container and encoding, S3 is unable to stream the video properly. If you record a video with the 'avc1.42E01E' codec and properties, it won't stream properly from the bucket, sending only a few kilobytes instead of loading the whole video.

The solution we came up with was to use a lambda to reencode the video after it had been uploaded. We also took the extra steps of splitting the video into chunks ready for HTTP live streaming (HLS) and doing adaptive bitrate streaming (ABS). After reencoding the videos, the lambda sends a message to the Bull.js queue which calls the backend which updates the DB with the new video URL. In the end, we had a massive ffmpeg command, but it worked like a charm. No more slow loading or unseekable videos.