As with much of the public sector/public sector-adjacent work, the pay will not be as remarkable as other companies in the private industry. I still make six figures as an L1 Software Engineer which I'm very grateful for, but it's in the very low six-figures and thus not as high as some entry level SWE positions that can be seen in any of the top private tech companies. Not to discredit my own downside, but I will say that the benefits+work/life balance do outweigh the pay discrepancy in my opinion, but if the cash value of your yearly salary is what's most important, you probably won't be the most fulfilled here.
(This is for prospective entry level software engineers) If your goal is to work on something very niche and you're coming in as an L1-L2, I don't think public sector work is going to be for you. The government and its contractors have many, MANY PhDs and senior level engineers that can produce very high-quality work in very niche fields. If you come here as a new professional, your goal should be to broaden your horizons as much as possible and find a field you really want to dig into, and that's true for many companies in all honesty.