These two titles increasingly appear on the same shortlist, and they solve different problems.
The question that separates them
Is the problem that nobody owns the revenue process, or that a specific thing you bought does not work in your company?
That is usually enough to decide.
What a GTM engineer owns
The machine between a lead arriving and a human closing: enrichment before contact, scoring, routing, the channels, the write backs, and the traceability from revenue back to its source.
They are accountable for a number. They talk to your team constantly and often to your customers. The work is continuous, because a revenue process is never finished.
What a forward deployed engineer owns
Getting a specific system to produce a result inside your environment: your data, your integrations, your edge cases, your compliance.
They are accountable for a deployment. The work is intense and finite by nature: it ends when the thing works and somebody else can operate it. The role exists because the distance between a product and one company's reality is full of things no vendor scopes.
Where they overlap
Both build. Both integrate. Both have to understand the business rather than just the tooling. Both are useless without decision rights.
The difference is what they are held to, and that difference changes who they report to, how you measure them, and how long you need them.
The order that usually works
If a purchased system is stuck, the forward deployed engineer unblocks it first. Then the GTM engineer owns the process it lives in.
The reverse order has a specific failure: unblocking a tool inside a process nobody owns produces a working tool that nobody uses, which is the most expensive form of success available.
A simple test for a shortlist
Ask each candidate: what are you accountable for at the end of an engagement?
The forward deployed engineer describes a system in production with a named owner and a runbook. The GTM engineer describes a number that moved and why.
Neither answer is better. They tell you which problem the person has been solving.
Which one MitHub places
Both, and they are separated on purpose, because the buying decision is different.
See the talent, split by whether they face your client or build inside your systems.