1. Introduction
2. Surveys
2.1. The DESI experiment
2.2. The Euclid spectroscopic survey
2.3. Tomography
2.4. The Planck experiment
2.5. The Simons Observatory
2.6. CMB Stage 4
3. Observables
4. Signal-to-noise forecasts
5. Fisher forecasts
5.1. Results for the ΛCDM model
5.2. Extension to CPL dark energy parameterization
5.3. Combining ARF and galaxy clustering with CMB lensing
6. Discussion
7. Conclusion