Technology of today
The technology of Cinders of the Catalysm is that of near-future, cassette-futurism retrofuturism. Yeah, that's a lot of -isms, but let me explain. The technology is how the 1980's would have imagined the future to be. That's what retrofuturism means. Cassette futurism is similar, but tries more closely to imitate the actual look of tech from the 1980's, particularly cars and computers.
Imagine the 1980's imagining the future, still keeping the to the design language of the 1980's and then someone vomited copious amounts of neon and chrome on top of it. That's the aesthetic and tech of Cinders of the Cataclysm.
Average tech level
For the average citizen tech isn't all too different to what we're used to in the 2020's. People have a personal communicator (PersoCom) that doubles as their computer, interface to The Web and mobile phone all in one, not unlike our smartphones.
However, persocoms are usually worn around the wrist, looking a lot like a 1980's digital watch. Most people have some form of interface that allows them to view the output of the persocom. This can be either internal (cybernetic eye with a HUD) or on a transparent surface like glasses. Very fancy persocoms have a holographic interface projecting in the air above it, but those are mostly for bragging rights and less for actual use. The privacy problem is obvious.
Some extremely expensive persocoms are built with nanocircuitry which can be embedded either into fabric or flesh. The persocom can be fully embedded into the palm of a hand or some other location. If linked together with other cyberware, the persocom can be completely invisible from the outside.
Cars still drive on roads and in fact do so even more than we are used to. "Off road" requires specialized vehicles, since the vast majority of cars, lorries and trucks are electrical and take power directly from the road while driving. If you go onto minor roads or even off-road, you suddenly rely on the car's battery, which is not designed to last for more than a couple of kilometers, because the car is meant to be driven on a powered road.
Specialized off-road vehicles can utilize long-lasting powercells that need either replacement or recharging after use, but these vehicles can last for hundreds or even thousands of kilometers on one charge. With replacable powercells you can also bring extra with you and replace it when you run out, although they are quite bulky, so this is more common for vehicles designed to visit the Shadowmark.
No gas or petrol
With the civilisation discovering the equivalent of nuclear energy (see Shadow Power) in their equivalent of "the middle ages", there was never any need for fossil powered technology. While fire and burning wood and coal played a part in the early stages of civilization, everything modern is electrical. Prior to The Cataclysm everything ran on shadow power, but with the advent of fusion energy, raw electricity became popular, especially in Fusion City, where shade-powered vehicles were banned.
Computers, while incredibly more powerful than ours of today, are bulky contraptions. Actual workstations and terminals are usually relatively large, boxy machines that make a lot of noise from cooling fans to clicky-clacky harddrives and tape-reels. Yes, tape-reels. Tapes are the storage media of the future in CotC. Capable of storing enormous amounts of data on magnetic strips, virtually all long-term storage is on large tape-reels in CotC. For short-term storage, mechanical harddrives serve the purpose well.
Tapes and cassettes
With the majority storage media being tape-reels, the prevailing removable storage is cassettes. Small, plastic containers holding a reel of tape. Digital storage exists, particularly in cybernetics, but it is incredibly expensive and really only used for small and important information such as trade secrets or the like. For cheap, large-scale storage, nothing beats the tapes. When trading music with your pals, you use cassettes.
Weapons and warfare
The primary weapon of warfare is actually melee, makeshift weapons like bats, knives and other blades. Some street-fighters also employ heavy chains and even use trash bin covers as makeshift shields. Access to firearms is heavily restricted, and although many criminals care not for the law and have access to black-market weapons, being caught packing is an ever present risk.
The vast majority of firearms in the city consist of either civilian grade pistols with small magazines and small caliber, or corporate security weaponry such as high-tech submachineguns and handguns.
Firearms are almost exclusively gunpowder-based, cartridge projectile weapons, with 9mm being the dominant projectile size for handguns and 5.56mm for assault rifles and mid-range rifles. There are more advanced weapons, but most of them were only science projects by the time of the Cataclysm. Laser weapons are the most developed ones and there are actual commercial-grade laser weapons in circulation. They are rare and expensive, but they do exist. Plasma and neutron weapons were only theoretical and only a few prototypes ever existed, mostly of giant, mounted cannon-type weapons.
We've skirted around the subject for a while now, but cybernetics are incredibly common in the world of CotC. Entry-level implants and prosthetics are comparatively affordable, and with cybernetics being a relatively new technology, the "fad" is strong. A lot of people want to modify themselves for social cred. About as many want to modify themselves to improve their life in some way. Whether it be a strong, robotic arm to perform their manual labor better, or a neurocomputer for better information processing at a desk job.
For more information on cybernetics, check Cybernetics.
Artificial Intelligence/Virtual Intelligence
Sadly, true artifical intelligence is not a thing. Self-aware computers are not technologically possible in the age of CotC. However, they've gotten pretty close to imitating it with a system called Virtual Intelligence, or VI.