Track · Services & data
Backend
The day-to-day engineering of backend services: keeping data correct under concurrency, staying fast under load, and degrading gracefully when a dependency doesn’t.
- Guides
- 6
- Sub-topics
- 4
- Diagrams
- 44
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Distributed Systems
Concurrency Control in Distributed Systems
Why local locks stop working the moment you scale past one instance, and how optimistic and pessimistic concurrency control pick up the slack — with isolation levels, lock types, and working Spring/JPA code.
Sub-topic
Reliability & performance
How services degrade under load and how to keep them alive.
Open sub-topic-
Backend
Backend Under Load: Eight Failure Modes
A system design interview field guide to how backends actually degrade — connection pool saturation, cache stampedes, lock contention, hot partitions, slow queries, network bottlenecks, and GC pauses — plus how they cascade into each other in a real incident.
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System Design
Distributed Systems & Backend Patterns
60+ patterns that keep production systems alive under failure, load, and scale — resilience, load management, caching, messaging, databases, distributed coordination, traffic routing, reliability, scalability, security, and observability.
Sub-topic
Concurrency
Threads, pools and the JVM concurrency toolkit behind every request.
Open sub-topic-
Java
Java Concurrency & Multithreading
End-to-end, internals-first: JVM memory architecture, CPU cache visibility, all six thread states, synchronized and volatile, wait/notify, thread pools, the full java.util.concurrent toolkit, ThreadLocal, CompletableFuture, the Java Memory Model, common bugs, and a full interview Q&A.
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JavaNew
Why wait() and notify() Must Be Called Inside synchronized
The lost-wakeup race that forces the rule, what the monitor’s entry set and wait set really do, why wait() must live in a while loop, notify vs notifyAll — and how Lock/Condition inherits the same contract.
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Career
Java Backend Developer + AI Roadmap
From core Java and concurrency to Spring Boot, databases, distributed systems, system design, production engineering, and AI — a granular roadmap focused on the concepts you actually need to understand to become a strong modern backend engineer.