Pros
Very competitive salary and benefits package. Flexible work environment, including ability to work from home when needed. Employee engagement and development is ACI's top priority - and I personally have benefited from this. Opportunity to travel to other ACI sites and to customers. My colleagues are talented, friendly and helpful. ACI's employees are consistently identified as its most valuable resource. ACI invest a higher percentage of revenue in R&D than most tech companies. Internal flexibility to move across product lines and be exposed to other payment domains and technologies. ACI's executives advocate and execute a bold, forward-thinking strategy. Frequent employee activities (eg. Friday treats, On-site fitness classes, Nights out, Summer and Christmas parties etc.). On-site gym and games room (foosball, pool, PS4). Agile development methodology. Strong career advancement prospects along multiple tracks (management, technical).
Cons
ACI is heavily audited (to the same level as financial institutions), so the IT environment (including user's laptops) is tightly controlled. However, the IT department put a lot of effort into ensuring that the environment allows users to do what they need to while meeting audit requirements. Also, due to audit requirements, development and release processes can be heavy, but again, this is an area of constant improvement with input from those affected by the process.