Let me suggest a slightly different strategy.
But first, I'll remark that I've twice had TM backups fail, so I no longer use TM.
I separate my work projects into their own folders, specific to the project. These individual folders I backup several times a day when I'm working on them by using "rsync" to differentially synchronize any modifications to two other computers. On one of these other computers I daily "rsync" these folders to two very large HDDs that includes everything I want backed up. I also "rsync" my work to several 400GB micro-SDXC cards (yes, the first time it takes awhile to write ~350GB to an SDXC card, but after the first time the "rsync"s do only differential backups and so are fast); one SDXC card I store in my vehicle, another I store in my wife's vehicle, one I carry with me at all times -- they are easily hidden as well as being easily swapped out for new SDXC cards. I also have three large HDDs, one on the west coast, one on the east coast, and one on the gulf coast. Every three to six months, or whenever I need to, I make new 400GB SDXC card differential backups and send them to the three coasts -- these SDXC cards include a bash script that "rsync"s the data on the card with the large HDDs at each location, making it a trivial job to keep the HDD backups on the three coasts up-to-date. Also I can readily snail mail the differential backup SDXC cards to the coasts in first class letters.
For truly personal and private information (which in today's world even includes photos) such as insurance, banking, financial, etc. data, I've written a bash script that encrypts each personal folder, splits it into manageably sized files, and "rsync"s these encrypted backups to the same computers, SSDs, HDDs, and SDXCs as before. The same bash script will verify the hash codes of the splits, merge the splits, decrypt the backup, and regenerate the personal folders, whenever I need them -- just a single Terminal command both backs up and encrypts as well as decrypts and restores. Since these encrypted backups are protected by 4096 bit RSA keys, I never worry about the personal information backups or computers being stolen as nobody has the computer resources to decrypt them.
I don't backup any applications, unless I wrote the code myself, as I figure I can always retrieve any third party applications if I need to. I also don't use the iCloud since nearly every cloud service has been hacked in the past -- I've even gotten away from storing photos in the cloud.
Now the above strategy may seem complicated and time consuming, but once set up it is quite quick and easy to maintain as everything is backed up using "rsync" in a differential manner. Since I don't use cloud services my personal information is not open to being hacked. And since my personal information is encrypted with strong encryption (4096 bit RSA) I don't worry about it being stolen. In addition, I always have a copy of encrypted personal information with me at all times, and in our vehicles, and I have copies of all backups at three external locations. In addition, I have backups under both Linux and the macOS. I feel this backup strategy is both robust and secure.
Perhaps the most important backup is to have a second computer that mirrors (via rsync) my laptop and all of its contents -- just in case either computer fails or is stolen.
Solouki
