Computer Skills
C++, C#, Java, R, MATLAB, SQL, Perl, JavaScript
Mathematical Knowledge
Statistical regressions, quadratic/linear programming, probability theory, matrix algebra, Black-Scholes option pricing math, risk-neutral valuation, random walks/Brownian motion, interest rate/yield curve math, modern portfolio theory, Monte Carlo simulation, big-O algorithm analysis, Bayesian statistics, stochastic calculus, high-dimensional space, pattern classification/machine learning (linear discriminant functions, neural networks)
If you get most of the skills above – your employment as quant is assured