Some of the best articles I read end up here. I believe this curated collection will level up your knowledge and skills.
How Zapier Automates Billions of Tasks A brief overview of technologies Zapier uses to automate things on scale. It’s not an extensive read, but I’m always interested in seeing the building blocks used by popular services under the hood.
Fairness in multi-tenant systems Provides an extensive deep dive into how AWS deals with bursts in traffic load. Different strategies helping to alleviate the pressure on servers when the load increases are discussed int the article. AWS Api Gateway, WAF, Load Balancer and CloudFront can all be used to balance the load on server and deal with anomalies.
Understanding database Indexes in PostgreSQL Gives an overview of the index concept in databases. The article is broad and deep, provides good explanation of different types of indexes.