Deliberate Omissions

Things a voice-agent roadmap usually includes that were left out on purpose:

Omitted	Reason
Writing the audio transport	Real-time audio over an unreliable network — jitter buffers, packet loss, echo cancellation, codec negotiation — is a specialist discipline, and none of it is what this material teaches. Use the framework’s transport and spend your attention on the conversation.
Training or fine-tuning speech models	A different discipline with a different cost structure. A hosted recogniser and synthesiser are better than anything you will train, and the interesting problems here are turn-taking, confirmation and escalation.
A managed voice agent platform	Step 2 covers when it is the right answer, and for a standard flow it often is. It removes the pipeline; it does not remove your call policy, escalation, confirmation strategy or evaluation.
Outbound calling campaigns	Technically a small change and legally a large one — nuisance-call regulation is real, varies by jurisdiction, and carries penalties. It belongs on step 3’s refusal list, not in a chapter.
Voice cloning of a real person	Consent, disclosure and impersonation risk that this material is not the place to work through. The disclosure at step 3 exists partly because a synthetic voice can be mistaken for a person.
Multilingual and code-switching calls	Genuinely valuable and it multiplies the evaluation problem before the single-language one is solved. Add it after step 12 exists, with recorded callers in each language.
Emotion detection and sentiment scoring	Frequently sold, weakly evidenced, and it invites decisions about a caller based on how they sounded. Escalating because a caller asked, or because the policy says so, is better grounded.
Payment capture over the phone	Card details spoken aloud is a compliance domain of its own. Step 6 says explicitly that this is a moment to handle deliberately rather than to store.
A managed observability platform	Step 14 covers when to adopt one. Four provider consoles plus your own ledger is what answers the client’s question at this size.
Kubernetes and autoscaling	Step 16 sizes one host in concurrent calls and falls back to the human line at the limit, which is a better failure than a slow scale-up on a live call.

If someone tells you this roadmap is incomplete without one of these, ask them what their agent does when the caller says they can smell gas.