Hopefully this is useful for someone. I needed an encrypted filesharing, similar to firefox send (which is unfortunately taken down due to abuse) but when i looked into deploying it myself, it seems like a fair bit of work to get it up and running so i decided to build something with minimal backend code (1 python lamda + 1 api gateway + 1 s3 bucket), no random 3rd party JS library.. Some cool things i learnt from building this project is the fact that you can acquire a POST signed policy to directly send file to S3, you can also add tag for your s3 objects and using bucket lifecycle rule base on object prefix, i can automatically expire objects and reduce backend code for that.