The innovative blockchain architectures emphasize maintaining scalability, usability, and interoperability in the projects and facilitate the development of custom blockchain solutions. As a result, technologies like Cosmos SDK and Substrate are becoming extremely popular and are widely been globally. Custom blockchain development is the buzz and the tech game needs to be prominent to ace the project expectations. So, let's focus on the two popular custom blockchain development technologies – Cosmos SDK and Substrate to understand their use cases and characteristics better.

What is Cosmos?

Cosmos is an open–source project maintained by a community of developers and users. As a decentralized network, it is meant for an independent, scalable, and interoperable blockchain system. Furthermore, it is a layer 0 blockchain designed for creating secure, scalable, and customizable blockchain applications. The cosmos network comprises several independent blockchains that are built using Cosmos SDK. All the blockchains associated with the network are viewed and tracked on the Cosmos hub itself.

Cosmos Software Development Kit (SDK) is a modular framework allowing developers to build custom blockchains. It is designed to be flexible and scalable with attractive features comprising multiple programming languages, powerful modular architecture, and an excellent application programming interface (API). The Tendermint Core which is the high-performance blockchain engine is used to power the Cosmos network.

What is Substrate?

The substrate is also an open–source framework designed to support the development of decentralized technologies. It acts as a modular and flexible platform for developing custom blockchain applications. Moreover, it provides a set of core building blocks along with the tools to make development, testing, and deployment tasks easier. The popular Polkadot network is built using Substrate tech stacks due to its high–performance runtime environment and rich set of development tools. 
Moreover, the decentralized governance model of the Substrate help user to participate in the decision–making process in the network for maintaining the security and integrity of the network. As a result, Substrate is a powerful and flexible platform to support the development of custom blockchain applications and is widely used by developers across the globe.

Cosmos v/s Substrate 

Though both these platforms have a common objective of building decentralized technologies yet have prominent differences which are as follows – 

Consensus Algorithm 

Cosmos is the decentralized network of independent, interoperable, and scalable blockchain systems with Tendermint, a Proof – of – Stake (PoS)  as the consensus algorithm. Wherein Substrate is the open–source framework for building custom blockchain applications The “Aura” which is based on the “grandpa” finality gadget is the consensus mechanism for Substrate.

Interoperability 

Cosmos facilitates interoperability between different blockchain systems with the use of the Inter-Blockchain Communication (IBC) protocol whereas Substrate does not natively support interoperability. However, developers can separately build custom modules to facilitate interoperability. 

Scalability

Cosmos is a highly scalable platform with the ability to process thousands of transactions in a second. On the hand Substrate is also designed to be scalable, however, the specific scalability of the Substrate depends on how developers implement it. Thus, it can be said that Substrate is less scalable than Cosmos.    

Smart Contract

The Cosmos SDK supports smart contracts through its Cosmos–based Ethereum Virtual Machine (EVM). On the contrary, Substrate does not have any form of built-in for smart contracts instead the developers have to use the Substrate runtime module library for building the custom runtimes for supporting smart contracts.

Blockchain Creation

The modular approach of the Cosmos SDK allows developers to choose suitable pre-built modules for developing desired blockchain network.  On the other hand, Substrate uses a more flexible and low–level approach to build the blockchain network from scratch.

Customization Flexibility 

Cosmos allows developers to have their own custom zones on the network along with various tools and libraries. However, Substrate offers a wide range of development flexibility through its modular components to build different types of blockchains and tailor them to the project specifications. 

Final Words 

Both Cosmos and Substrate are powerful blockchain development platforms which some key differences. However, both these platforms provide a high level of flexibility and customization, alongside having active and supportive communities. Thus, what platform is best for your project would be based on the nature of the project, the capabilities it is expected to have, and the purpose it needs to serve. This can be well–defined through consultation with blockchain development experts.