The cons from my perspective are :
1. Salary is low , almost like a mass-recruiter organization. It has the branding of a product company: you will work on Ericsson products and deliver them, maybe also test on products of other vendors. But, it will look and feel like a services based company from inside.
2. Annual hikes are low : Single digits on an average , with early double-digit hikes only when you get promoted.
3. It is difficult to get a promotion unless you have good relationship with your Line Manager. Mind you, Line Manager is not your Project Manager in most cases. So, they will most probably have no clue on what you're working or how important it is in the grand scheme of things (at a project level).
4. For Testing , most projects employ manual testers only with little attention to Automation Testing or Performance Testing. You will find yourself lacking at the time of leaving if you do not upskill into Cloud technologies and more. An example is that majority of the customer projects do not have CI/CD pipelines (in Dec 2021!).
5. For people who have been working on specific Ericsson products, you'll be pigeonholed into the same thing. This will start to feel restrictive to individual growth in a few years.
6. Flexible Timings = you might need to work at weird times and support for longer hours. Personally speaking, my longest working day was of 18 hours with barely some time to sleep.
7. QA/Testing Team is given less importance and is unappreciated. You'll get rewards and awards for doing much more than what your job level requires, but no promotions or good hikes. It is a thankless job.
8. Opportunities for Niches in QA are less. Automation/Performance/Security testers are in high demand and low supply at Ericsson. They try to fill it from lateral hires (with more pay and higher designation for lesser experience) instead of giving already skilled people a chance to work (or even shadowing and learning from existing people)
These issues perhaps do not exist in the R&D division of Ericsson India Global Services.
