As someone who's worked for big blue in a couple of countries and on two non-consecutive occasions ...
Its kind of interesting. It's such a huge organisation that there's room for multiple different streams, trends and directions all the time. There's also a massive disconnect between the people producing tech products, the 'research labs' and the services arms, the latter of which seem to have the focus of upper management more than any others.
The 'labs' are there AFAICT mostly to make the company look good and try to achieve headline-grabbing things like Watson. Very little of this feeds through to the trenches of the tech production lines, which tend to vary from the obvious corporate/enterprise software type setups (monstrously huge, cumbersome software which does things useful to enterprises but takes a long-ass time to adapt, gets its lunch eaten by startups, which then get bought, replace the incumbent, start to grow ... rinse and repeat), to large departments which resemble nothing so much as academia, complete with dingy corridors that haven't been redecorated since the 80s, which have miniscule output expectations and release new products with an absolutely glacial cadence.
Meanwhile the real corporate focus is on selling services and consultancy.
I feel somewhat fondly towards IBM, and I'm glad to have worked for one of the biggest names in our industry. They always treated me well (though make no mistake, they'll lay off thousands in a heartbeat if they think they can save a dollar). At the same time the organisation did feel a bit pathological, particularly last time I dipped my toes in, it felt like a giant in managed decline. Still vast revenues and enough money to cast about looking for lifelines, but ultimately directionless. Perhaps things have changed since 2015... perhaps the redhat acquisition has altered the focus. I'm guessing not though.