The phrase "astounding development" is correct and usable in written English.
You can use it to describe a significant or surprising advancement in a particular field or situation.
Example: "The scientists announced an astounding development in renewable energy technology that could change the future of energy consumption."
Alternatives: "remarkable progress" or "incredible breakthrough."
Maybe, in light of the astounding development in Cleveland, Davey Lopes would like to reconsider his old-school (read that old-fashioned) thinking.
Last year, for the first time in decades, the number of people riding the subway actually slightly declined — an astounding development in a growing city with a booming economy.
One of many questions surrounding the big news this morning that Russia has called on Assad to destroy his chemical arsenal – an astounding development, considering that a week ago president Putin was denying evidence of a chemical attack – is, to what extent the Russians are working with US secretary of state John Kerry and other US diplomats on the issue.
For better and worse, the Pacific Railway Act, the Morrill Act, and the Homestead Act provided the foundation for the most astounding development of industry, education, and agriculture in human history.
It promises to be an astounding development.
The same question was asked at the recent 40th anniversary celebration of BRAC, the astounding development success story from Bangladesh.
He talked about how failure led to the pursuit of knowledge, and the astounding developments in medicine produced with the courage and imagination that are the mark of great scientists.
Despite these astounding developments, it is clear that RNAi is not the ultimate panacea for the contemporary cell biologist.
A quick mobilization at airports around the country, within hours, is an astounding modern development that is possible through the powers of social media (largely Facebook).
The last decade has ushered in astounding growth in the amount of energy-related data, along with game-changing developments in machine learning and other innovative data science techniques.
Wars provide the sharpest example of the innovative power of government spending: astounding new developments in drone and prosthetic technology let alone the jet engine are a bittersweet testament to that.
