Retrospective on building a system that automatically identifies low-performing SSP inventory and throttles traffic to improve contribution margin. Covers the evolution from Imp Cost Ratio to a predicted contribution margin rate approach.

How Route Tables decide traffic paths inside a VPC, the role of Internet Gateway and NAT Gateway as external exits, and the actual meaning of Public/Private Subnet.

How VPC simulates a private network boundary by combining IP CIDR, Subnet, and Tenancy. Includes vendor naming map across AWS / GCP / Azure / Alibaba.

Covers technical indicators (RSI, SMA Cross, MACD, Bollinger Bands) for reading price movements, composite signal design, and a comparison of three strategy types across different time horizons.

Covers factor scoring methods (Z-Score, Rank) for combining indicators into a single score, plus the basics of rebalancing and asset allocation.

Covers the formulas and interpretation of CAGR, MDD, Sharpe Ratio, and other backtest metrics, plus five common backtesting pitfalls.

Covers the role of price momentum and dividend yield as factors in quant investing.

Covers how to judge whether a company is cheap (valuation) and whether it earns well (quality) — formulas and interpretation of PER, PBR, PSR, ROE, ROA, and debt ratio.

Covers OHLCV data as the starting point of quant investing, the difference between simple and log returns, and the meaning of market capitalization.

A three-step pattern combining dual write and fallback read to transition data formats in live services without downtime.