Permanently installed fiber-optic systems have been commercially available in the oil field since the early 1990s, with the bulk of the deployments providing fiber-optic distributed temperature. Over 1,200 installations have been deployed by one service company alone. Such installations have reduced the need for intervention via logging tools and have given crucial insights into wellbore integrity and reservoir production. Consequently, a prime application of fiber technology should be in deepwater fields, where intervention can be prohibitively expensive, if not impossible, but that has yet to prove true. The reluctance to incorporate downhole fiber appears to be because of limitations of technology relating to cables, deployment, acquisition, and interfacing. These barriers are slowly being eliminated, and a small number subsea wells have now been implemented with in-well fiber. Specific technology breakthroughs have been pertinent to subsea: cables that withstand hydrogen darkening, fiber connectivity interfaces to subsea trees, and increased deployment options for acquisition hardware. Deployed subsea solutions have included optic monitoring for cementing, integrity, and cleanup. A roadmap to eliminate some remaining obstacles includes the needed interfaces for power and telemetry to the SPS and the interpretation of temperature data on complex subsea fields. That roadmap needs to take into account the full range of hardware opportunities available for subsea applications and not exclusively fiber optic. Indeed, the optimal completion solution need not involve sandface fiber at all.