There's 4 components to a Civilian build. First component is your Ethics. Most players opt to have Egalitarian(if not Fanatic Egalitarian) for Utopian Abundance Living Standard. This applies a 20% Job Efficiency boost to Civilian strata(so your 20 starting Civilians are effectively 24) and yields 1 Unity and 1.5 Research per 100 Civilians at the cost of 1 CG in upkeep(and 1 CG of upkeep to all other strata). To cut down on that upkeep, you take the second component in Seasonal Dormancy Trait. Seasonal Dormancy can only be applied to Mammalian or Reptile species but cuts Pop Upkeep by 15%(for those with Jobs) and those w/o Jobs by 75%. Meaning instead of 1 CG, it's 0.85 CG per 100 Pops w/ a job and 0.25 CG for Civilians. This also applies to Food too so instead of 1 Food, you'll only consume 0.85 and 0.25 with Civilians so it pays to basically have as few jobs as possible.
The third component to a Civilian build is the Mercantile Tradition. Mercantile Tradition unlocks Consumer Benefits, a Trade Policy you will want to adopt because it converts Trade directly into Consumer Goods at the rate of 4 Trade: 1 CG. You'll need to make up the loss in Energy via Technician jobs but the Mercantile Tradition provides more than just the Trade Policy. You'll get +1 Trade and bonus Amenities per 100 Civilians at the cost of 0.10 CG upkeep(which CANNOT be reduced via Seasonal Dormancy). The fourth and key component is the Monument. The Monument applies Culture Worker effects to Civilians and the reason players pick Fanatic Egalitarian is because Civilians gain +2 Trade from Fanatic Egalitarian. Your Moderate Ethic pick is entirely up to you but I'd recommend Xenophile for two reasons. 1) You generate additional Trade Value from the Ethic itself but 2) You gain 0.625% Pop Upkeep per 100 Civilians. Stack enough Civilians and well... yeah... you'll eventually reach -90% Pop Upkeep threshold. The Monument also grants 0.50 Unity per 100 Civilians at the cost of 0.25 CG in upkeep(which like Mercantile cannot be reduced with Pop Upkeep because its effectively a job upkeep).
That is why Civics like Civil Education contain a Councilor post with Job Upkeep because it applies to Civilian modifiers such as that. Now without Civil Education, your Civilians will be producing 3+ Trade Value, 1.5 Unity, 1.5 Research(each) and Amenities for 0.25 + 0.1 + 0.25 or 0.6 CG(even less if you take Xenophile). Civil Education's Academies add 0.50 Research(each) for 1 CG upkeep and can stack up to 3 times. Meaning you can get 3+ Trade value, 1.5 Unity, 3 Research(each) and Amenities for 3.6 CG in upkeep. Of that 3.6, 3.35 is effectively Job Upkeep. The Civil Education Councilor post can cut that by 5%(level 10; 10% in total with Prosperity Tradition), resulting in roughly 3 CG in upkeep overall. That cannot match the output of Researchers, Traders and what not but Civilians have an **unlimited** cap and therein lies the early game **power** of a Civilian build because you can generate gobs of Unity, Tech and what not for little to no cost.
You then pair it with Parliamentary Systems to form Factions(which generate Unity that with Fanatic Egalitarian and the Civic have their Unity output almost doubled) and you can roll through Traditions so fast it's mindboggling. Can easily ascend by 2230, if not sooner.
