Galloway, M.M.GallowayAndersen, K. J.K. J.AndersenAurlien, R.R.AurlienBanerji, R.R.BanerjiBersanelli, M.M.BersanelliBERTOCCO, SARASARABERTOCCOBrilenkov, M.M.BrilenkovCarbone, M.M.CarboneColombo, L. P.L.L. P.L.ColomboEriksen, H. K.H. K.EriksenEskilt, J. R.J. R.EskiltFoss, M. K.M. K.FossFranceschet, C.C.FranceschetFuskeland, U.U.FuskelandGALEOTTA, SamueleSamueleGALEOTTAGerakakis, S.S.GerakakisGjerløw, E.E.GjerløwHensley, B.B.HensleyHerman, D.D.HermanIacobellis, M.M.IacobellisIeronymaki, M.M.IeronymakiIhle, H. T.H. T.IhleJewell, J. B.J. B.JewellKarakci, A.A.KarakciKeihänen, E.E.KeihänenKeskitalo, R.R.KeskitaloMAGGIO, GianmarcoGianmarcoMAGGIOMaino, D.D.MainoMARIS, MicheleMicheleMARISMennella, A.A.MennellaParadiso, S.S.ParadisoPartridge, B.B.PartridgeReinecke, M.M.ReineckeSan, M.M.SanSuur-Uski, A. S.A. S.Suur-UskiSvalheim, T. L.T. L.SvalheimTAVAGNACCO, DanieleDanieleTAVAGNACCOThommesen, H.H.ThommesenWatts, D. J.D. J.WattsWehus, I. K.I. K.WehusZACCHEI, AndreaAndreaZACCHEI2025-03-032025-03-0320230004-6361http://hdl.handle.net/20.500.12386/36355We describe the computational infrastructure for end-to-end Bayesian cosmic microwave background (CMB) analysis implemented by the BeyondPlanck Collaboration. The code is called Commander3. It provides a statistically consistent framework for global analysis of CMB and microwave observations and may be useful for a wide range of legacy, current, and future experiments. The paper has three main goals. Firstly, we provide a high-level overview of the existing code base, aiming to guide readers who wish to extend and adapt the code according to their own needs or re-implement it from scratch in a different programming language. Secondly, we discuss some critical computational challenges that arise within any global CMB analysis framework, for instance in-memory compression of time-ordered data, fast Fourier transform optimization, and parallelization and load-balancing. Thirdly, we quantify the CPU and RAM requirements for the current BEYONDPLANCK analysis, finding that a total of 1.5 TB of RAM is required for efficient analysis and that the total cost of a full Gibbs sample for LFI is 170 CPU-hrs, including both low-level processing and high-level component separation, which is well within the capabilities of current low-cost computing facilities. The existing code base is made publicly available under a GNU General Public Library (GPL) license.STAMPAenArticle10.1051/0004-6361/2022431372-s2.0-85164119295https://www.aanda.org/articles/aa/full_html/2023/07/aa43137-22/aa43137-22.htmlhttps://api.elsevier.com/content/abstract/scopus_id/851641192952023A&A...675A...3GFIS/05 - ASTRONOMIA E ASTROFISICA