A product engineer usually develops capabilities for a product’s broader user base. A solutions engineer often helps evaluate and demonstrate a solution during a customer decision process. An implementation engineer focuses on deploying and integrating it. An FDE role can overlap with these responsibilities while owning substantial engineering work in a specific customer context. Boundaries vary by organization.
The useful question is who owns which outcome. Who discovers requirements? Who writes and maintains integration code? Who approves access? Who accepts the pilot? Who responds when it fails? A clear ownership map prevents the engineer from becoming an undefined support channel for every problem.
Technical depth and communication reinforce each other. You need enough implementation knowledge to diagnose a broken request and enough customer understanding to know whether fixing it solves the actual workflow problem.
Exercise: map ownership for discovery, API integration, security review, pilot acceptance, and ongoing operations in a simulated engagement.
Check: every important decision has an identified owner, and you distinguish collaboration from unlimited personal responsibility.