TLDR

Celestia is a pluggable data availability layer for any chain to compose on. It flips the paradigm of combining execution, consensus and data availability into a single layer 1. The modular approach allows devs to focus strictly on the application layer and not the consensus layer. The team is extremely diverse with experience from scaling blockchains, Eth 2.0, Tendermint, Harmony and much more.

Celestia design and future roadmap

• Key Features: data availability proofs, erasure coding, limited execution environment, light client security guarantees similar to that of full node,
• EVM rollups: would send attestations to Ethereum mainnet - cheaper than posting the data as these are just signatures attesting to the data...