  We report the detection of the full orbital phase curve and occultation of
the hot-Jupiter WASP-100b using TESS photometry. The phase curve is isolated by
suppressing low frequency stellar and instrumental modes using both a
non-parametric harmonic notch filter (phasma) and semi-sector long polynomials.
This yields a phase curve signal of (73 +/- 9) ppm amplitude, preferred over a
null-model by deltaBIC = 25, indicating very strong evidence for an observed
effect. We recover the occultation event with a suite of five temporally
localized tools, including Gaussian processes and cosine filtering. This allows
us to infer an occultation depth of (100 +/- 14) ppm, with an additional +/- 16
ppm systematic error from the differences between methods. We regress a model
including atmospheric reflection, emission, ellipsoidal variations and Doppler
beaming to the combined phase curve and occultation data. This allows us to
infer that WASP-100b has a geometric albedo of A_g = 0.16 (+0.04, -0.03) in the
TESS bandpass, with a maximum dayside brightness temperature of (2710 +/- 100)
K and a warm nightside temperature of (2380 [+170, -200]) K. Additionally, we
find evidence that WASP-100b has a high thermal redistribution efficiency,
manifesting as a substantial eastward hotspot offset of (71 [+2, -4]) degrees.
These results present the first measurement of a thermal phase shift among the
phase curves observed by TESS so far, and challenge the predicted efficiency of
heat transport in the atmospheres of ultra-hot Jupiters.
