Example of Real Question you should ask your engineer if there is something about Y-Combinator work to be done...

Y-Combinator-this-Question-Async-Await.js

const log = function (message, s) {
	process.stdout.write(`${String(message).padEnd(17)} : ${s || ''}\n`);
};

const YCombinator = async function (realWork) {
	log('start', this);
	return await (async function (cb_x) {
		log('inside', this);
		return await cb_x.call(this, cb_x);
	}).call(this, async function (cb_y) {
		log('outside', this);
		return await realWork.call(this, async function (...subargs) {
			log('out_in_side', this);
			return await (await cb_y.call(this, cb_y)).call(this, ...subargs);
		});
	});
};

const factorialWithYCombinator = async function (itself) {
	log('real_work combo', this);
	return async function (n) {
		if (n < 2) {
			log('real_work finish', this);
			return 1;
		}
		log('real_work', this);
		return n * (await itself.call(this, n - 1));
	};
};


(async () => {
	
	const calculation = await YCombinator.call('"this" -> combine', factorialWithYCombinator);
	
	debugger;
	log(await calculation.call('"this" -> work', 5), 'done')
	
})();

Y-Combinator-this-Question.js

const log = function (message, s) {
	process.stdout.write(`${String(message).padEnd(17)} : ${s || ''}\n`);
};

const YCombinator = function (realWork) {
	log('start', this);
	return (function (cb_x) {
		log('inside', this);
		return cb_x.call(this, cb_x);
	}).call(this, function (cb_y) {
		log('outside', this);
		return realWork.call(this, function (...args) {
			log('out_in_side', this);
			return cb_y.call(this, cb_y).call(this, ...args);
		});
	});
};

const factorialWithYCombinator = function (itself) {
	log('real_work combo', this);
	return function (n) {
		if (n < 2) {
			log('real_work finish', this);
			return 1;
		}
		log('real_work', this);
		return n * itself.call(this, n - 1);
	};
};

const calculation = YCombinator.call('"this" -> combine', factorialWithYCombinator);

debugger;
log(calculation.call('"this" -> work', 5), 'done');

So, we should ask about this keyword, whether we will use from "combine" or from "work".
And might be the aswer is: we should use the Factory of Y-Combinators :)
But then what will be this for that factory.