Until Sunday, Oct 18: code CRACK50 takes 50% off.

Learn how real software is built, from your first data structure to a system that survives production.

A 230-page engineering handbook for people who already code and want to think like engineers. Every idea is shown in Python, Java, Go and Elixir side by side, so you learn the concept, not one language's syntax.

What's inside (28 chapters in 6 parts):

• Foundations: how software runs, types and memory, data structures, OOP vs functional

• Core skills: Git, testing, debugging unfamiliar code, error handling, reading codebases

• Data: SQL, transactions, NoSQL, caching

• Building systems: REST API design, authentication, background jobs, concurrency, distributed systems

• Production: performance, security, logging, CI/CD and containers, refactoring, system design trade-offs, production incidents, code review

• 2 full case studies: a notification service end to end, and scaling an app under load

• Exercises after every chapter, from foundation to challenge level

Why engineers read it:

• Adding a language? See how Python, Java, Go and Elixir solve the same problem: concurrency, errors, memory and data.

• Making design calls? The trade-off chapters and two production case studies give you the reasoning, not just the patterns.

• Leading or mentoring? One book that connects everyday code to the systems it runs in.

• Interviewing for your next role? Refresh system design, concurrency and databases in an evening.

Format: 232-page PDF, readable on phone, tablet and desktop. Instant download.