Last-mile deployment is adapting a working product to a customer’s real systems until the outcome the customer paid for actually lands. Product engineering ships the capability; last-mile work keeps it alive after it hits the customer’s environment. Field success needs a verifiable completion condition and LLM-as-a-judge evals, not a demo that worked once.
Why it exists
Customer environments rarely match the demo - fragmented data, legacy workflows, compliance constraints. Shipping the feature is not the same as the customer getting value.
Who closes it
A Forward Deployed Engineer embeds on-site: builds, configures, and keeps it running. Without that embedding, implementations stall on blockers that never came up in discovery calls.
Related
Measurable scoping before you build: how to plan and scope a build with an LLM. Field success needs evals, not vibes: five metrics for an agent eval pipeline.