Don'ts
I never work for the financial sector or related branches (insurance industry etc.). Not on principle, apparently it is an uninspiring domain to me.
No projects using Scrum. I'm not going into it here. Other people give a better description of this micromanagement abomination. It doesn't mean, I underestimate communication and its consequences, though.
...and Do's
Anything else - large with dozens of people or small-scale - will probably do, in particular if utilizing technology or achieving real R&D. Some of the industrial sectors I have worked for can be found on the project page. The following paragraphs will illustrate more recurring topics.
Image Processing & Computer Vision
I have been gathering experience in this field for more than 20 years, utilizing classical and machine-learning based (esp. neural networks) methods. The environment can be characterized as industrial (in a quite multifaceted sense). It also includes some particular video-related topics. No medical imaging up to now, though.
3D Data Processing & Visualization
Among others, this topic came up from a demand for representing terrain and air-spaces for navigational devices and from data-driven visualizations of buildings and equipment. Apart from the visual part, algorithmic work makes a regular companion. Examples here are volumina and closest distance calculations, shadow volumes and other items from computational geometry. Genetic algorithms for global optimization are noteworthy in this context too. I have acquired some experience with large data sets (OoC techniques).
Multi-Platform Development
I have a record in touching different aspects of this subject. First, there is general cross-platform coding including the development of largely agnostic software libraries. Porting is another variation I can do even against the moving target of parallel code development for the original platform (requires also a good, disciplined team). Porting depends also on a sufficient command of refactoring techniques.
Technology Combinations & Changeovers
In a sense complementary to the last section, this includes glueing technologies (e.g. between native and managed code on Windows). Refactoring and replacement of base technologies (DirectX <-> OpenGL, WPF<->Qt, C++ <-> C# etc.) form another aspect. I have also a proven track developing prototypes and conducting them to industrial-strength solutions.