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Backend interview guides, free to read
8 structured tracks with 435+ articles covering Java, Spring Boot, system design, databases, Kafka, distributed systems, DevOps, and low-level design. Read in order or jump to the topic you need today.
Core Java
Eleven modules that build on each other, from how the JVM runs your first class to virtual threads in Java 21. Read them in order and nothing later will feel like magic.
55 articles · 634 min read
Open trackSpring Boot
Twelve modules from HTTP basics to cloud deployment. One running BookStore API grows with every chapter so concepts compound instead of resetting.
48 articles · 525 min read
Open trackSystem Design
Twelve modules from interview frameworks to cloud-native production. StreamHub grows with every chapter — one platform, every building block, every classic product design.
60 articles · 765 min read
Open trackLow Level Design
Twelve modules from interview framework to architect-level patterns. One CampusOS platform grows with every chapter — parking, booking, caching, and games all plug into the same design vocabulary.
67 articles · 852 min read
Open trackDatabases & Caching
Ten modules from your first SQL query to Redis clusters, Elasticsearch search, and DynamoDB at scale. VaultCommerce grows with every chapter.
51 articles · 556 min read
Open trackKafka
Ten modules from async messaging fundamentals to production Kafka operations. VaultCommerce's event backbone grows with every chapter — one platform, zero gaps.
52 articles · 572 min read
Open trackDistributed Systems
Twelve modules from partial failure to architect-level playbooks. One ShardPay payment ledger grows with every chapter — every failure mode you'll face at scale.
54 articles · 562 min read
Open trackDevOps
Twelve modules from culture and Linux basics to Kubernetes, GitOps, and SRE. One BookStore API grows with every chapter — the same app you built in Spring Boot, now shipped and operated at scale.
48 articles · 507 min read
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