Protocol engineering, security, and DeFi are three different jobs
Ask most people what a career in web3 looks like and they picture one thing: a developer writing Solidity to deploy a smart contract. That is a real and important role, but it is one job among many, and treating it as the only entry point causes a lot of capable people to rule themselves out unnecessarily. Protocol engineering, building the underlying chains, rollups, and core infrastructure that everything else runs on, is a distinct discipline from application-level smart contract work, closer to systems and distributed-systems engineering than to typical web development. It requires understanding consensus, networking, and state management at a level most application developers never need to touch.
Smart contract auditing and security research is its own specialty, and honestly one of the most consistently in-demand and high-paying corners of the entire industry. Auditors read other people's contract code looking for the specific ways it can be drained, manipulated, or bricked, a skill that combines deep protocol knowledge with an attacker's mindset. Separately, DeFi and quantitative roles exist for people who understand market mechanics, on-chain liquidity, and trading strategy well enough to build or operate protocols and desks that move real capital. These three roles, protocol engineering, security, and DeFi/quant, barely overlap in daily work, even though all three get lumped under 'blockchain developer' from the outside.