Original post by winterscomingBusiness consulting would be something like accounting, business management, finance, etc. Tech consulting would be about software engineering, network engineering, devops, testing, etc. But IBM don't really control the projects - it's all down to the requirements of their clients. If you're in a technical role you probably wouldn't be involved in the business side of things though - they'll have project managers and business analysts for that side of the job.
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For example, a typical project for IBM might be something like building a new system to handle healthcare data for the NHS - e.g. writing software which can pull in data from thousands of hospitals across the country, check the quality of that data, store it in a database, produce reports, manage patient records, integrate with other NHS systems, make sure the data is secure and meets GDPR standards, ensuring the system is robust and quick to recover from a failure, make sure the system can handle the load of large quantities of data being accessed by tens of thosuands of users, etc.
There's no particular limits on what kind of technology it could be - it might be a website, or mobile app, desktop app, a set of distributed microservices, or maybe some cloud lambdas in AWS/Azure, The platform could be *nix, or Windows, or maybe solaris. The language could be anything from Java, Python, C#, Javascript, C++, or even something a bit less well-known like Delphi. One thing you'll often find with consultancies is that you're potentially exposed to a lot of different tools and technologies - although realistically in the first couple of years you'd probably stick with something like Java or Python and web technologies because that'll most likely be where the majority of their clients are working.