It is a complex system, but it certainly makes a change.

这是个复杂系统，但肯定有所改进。

《柯林斯英汉双解大词典》

Developing a distributed file system is a complex endeavor, but it's immensely valuable if the right problems are solved. Ceph's goals can be simply defined as

开发一个分布式文件系统需要多方努力，但是如果能准确地解决问题，它就是无价的。

youdao

We test this carefully but in such a complex system there are sometimes places where we could do better.

我们进行了精心的测试。但对于如此复杂的系统，有时难免会出现需要改进的地方。

youdao

It is a complex system of public and private insurance plans, regulated by the government but still giving individuals a good deal of choice.

VOA: standard.2009.09.28

But it's also a very complex system.

NPR: Trouble with Your iPhone? Take a Class

The trouble is that it takes decades to develop a complex new defence system but threats change quickly.

ECONOMIST: Defence procurement

Green is realistic about the difficulty of getting users to trust a new, complex cryptographic system, but believes that adoption of Zerocoin is possible.

FORBES: Connect