Sorlock (Sorcerer / Warlock) is an extremely common multiclass combo.
It has great synergy, and it has a unique combo that nobody else gets.

Sorcerers can convert between sorcerer points and spell slots.
Warlocks get their pact slots back on a short rest.

So, once you are level 3 sorcerer, you can:
- convert your two warlock pact slots into sorcerer points
- convert those sorcerer points into spell slots
- short rest to get your warlock pact slots back
- repeat

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The real kicker for this, is that you can bank a bunch of spell slots ... above your normal daily limit.

In other words, you take a long rest, and you (as a 3rd level sorcerer), start the day with 4 first level slots, and 2 second level slots, and 3 sorcerer points.
You are also a 5th level warlock, and get two pact slots at 3rd level each.

So, convert your 3 sorcerer points into a 2nd level slot.
You now have 4 first level slots, and 3 second level slots.

Next, you can convert one pact slot (3rd level) into 3 sorcerer points, and then to another 2nd level slot.
Repeat for your other pact slot.
You now have 4 first level slots, and 5 second level slots.

Short rest to get your pact slots back.
Repeat as needed.

Spend the morning doing this, and you can bank a pretty big bucket of spell slots to go adventuring with.
Neat-o.
Of course, it all resets when you take a long rest.

There is an alternate build called the 'coffeelock', where you never take a long rest, and build an effectively unlimited number of spell slots.
But not everyone considers it a legal build.

Anyhow, yes, it's a very viable build.
Usually, the build has more levels in sorcerer than warlock.
e.g. Sorcerer X / Warlock 2, but you can do different splits, depending on what you want.