When Bugs Cost Billions: Real‑World Software Failures and Their Fallout

A bug can evaporate $5 billion on the spot; A design‑level bug has caused six deaths; Failed debugging can threaten the world.

What is the biggest bug you have ever written in your career?

Brave developers constantly create miracles, but sometimes those miracles turn into catastrophes.

People feel that as long as you exist, the world is safe from death.

Bug Is Huge, Please Hold On

How big can a bug actually be?

Some data‑dump or shipping‑logic bugs can make hundreds of thousands disappear instantly.

Have you ever seen a bug that made you lose money so badly you wanted to drown?

A payroll software once doubled salaries, overpaying more than 20 million yuan.

The payroll slip had already been generated, just waiting for a batch request to the bank.

Suddenly, all kinds of absurd bugs appeared: water‑gate failures, high‑speed train collisions, even near‑civil wars in African nations.

Globally, there is no "largest" bug—only bigger ones.

In 2016, Excel caused errors in tens of thousands of genetics papers because gene names like SEPT2 or MARCH1 were auto‑converted to dates.

Outside academia, bugs have been even more dramatic.

In 1996, the Ariane 5 rocket exploded 37 seconds after launch due to an integer overflow.

The failure erased $7 billion of development cost and $5 billion of equipment.

Historical bug lists show that almost every entry involves millions or billions of dollars lost.

Sometimes bugs even cause deaths.

From 1985‑1987, the Therac‑25 radiation therapy machine had a software interlock bug that increased radiation dose by 100 times , killing at least six patients.

Another near‑catastrophe: the 1983 Soviet false alarm that almost triggered a nuclear war.

△ Stanislav Yevgrafovich Petrov

On September 26, Soviet radars detected five missiles launched from a U.S. base.

Petrov judged the warning a false alarm and did not report it, preventing a potential global conflict.

“It’s Not a Bug, It’s a Feature”

After seeing those massive failures, everyday bugs like email loops feel gentle.

Even a lottery‑program bug that caused a social media “death” is trivial compared to the above.

In gaming, bugs are often called “features”.

△ Genshin Impact Fishing‑Rod Bug

Some major game studios even sell bug‑themed mugs.

Players comment that bugs reflect complex game rules and interactions.

△ Dwarf Fortress Cat Death Incident

Outside games, users sometimes complain angrily when a bug is fixed.

Finally, returning to the question “What’s the biggest bug you’ve written?” some answer humorously: “Choosing to become a programmer.”

What’s the biggest bug you’ve written? — I chose to become a programmer.

Software bug list: https://en.wikipedia.org/wiki/List_of_software_Bugs

Reference link: https://www.zhihu.com/question/482967292