Verdict: Rust
Rust vs Go for blockchain:
Rust dominates.
Solana, Polkadot, Substrate, and Foundry are all Rust. Memory safety + no GC pauses + zero-cost abstractions make Rust the language of choice for consensus-critical code.
Why Rust wins for blockchain
No GC pauses in consensus
A GC pause during block production or validation can cause slashing (losing staked tokens) or missed blocks. Rust's deterministic memory management eliminates this risk entirely.
Memory safety in financial code
Integer overflow, buffer overflows, and use-after-free bugs in financial code are catastrophic. Rust catches these at compile time. Solana's choice of Rust was partly motivated by this: financial bugs are irreversible.
Zero-cost abstractions for cryptography
Ring, dalek-cryptography, and the wider Rust crypto ecosystem provide elliptic curve operations, hashing, and ZK proofs with performance competitive with hand-tuned C. No overhead from abstraction layers.
WASM compilation
Rust compiles to WebAssembly more naturally than Go (Go's WASM output requires a runtime bootstrap). Polkadot uses Rust-to-WASM for on-chain logic. Solana programs are Rust compiled to BPF.
Blockchain ecosystem
Rust
✓Solana (all programs in Rust)
✓Polkadot / Substrate framework
✓Foundry (EVM toolchain)
✓NEAR Protocol
✓StarkNet / Cairo
✓IBC protocol implementations
Go (Cosmos ecosystem)
✓Cosmos SDK (build Cosmos chains in Go)
✓Tendermint BFT consensus engine
✓Ignite CLI (scaffold Cosmos chains)
✓Osmosis DEX
✓Celestia (modular blockchain)
✓Ethereum client Geth
Exception:If you're building on Cosmos, Go is not optional. The Cosmos SDK, Tendermint, and all the tooling are Go. You can write application logic in other languages through CosmWasm (Rust contracts), but the chain infrastructure is Go.