Pick a skill, do a 15-min drill.
Targeted practice on one topic at a time. The AI adapts depth as you go and scores every answer so you can see exactly where you’re weak. No fluff, no replays of questions you already nailed.
Programming languages
- AllJavaOOP · Collections · Threads · JVM internals
- AllPythonIdiomatic Python · async · context managers
- AllJavaScriptClosures · async · event loop · prototypes
- IntermediateTypeScriptGenerics · types · type guards · utility types
- AllReactHooks · Suspense · server components · perf
- IntermediateNode.jsEvent loop · streams · clusters · perf
- AllGo (Golang)Goroutines · channels · interfaces · stdlib
- AdvancedRustOwnership · borrow checker · traits · async
- AdvancedC++Memory · RAII · templates · STL
- IntermediateAngularComponents · RxJS · change detection · signals
- IntermediateGraphQLSchema design · resolvers · N+1 · federation
- IntermediateSpring BootDI · beans · MVC/REST · JPA · security
- Intermediate.NET / C#C# · async/TPL · ASP.NET Core · EF Core
- AllPHPOOP · Composer · Laravel · PDO · security
- IntermediateRuby / RailsBlocks · metaprogramming · Rails · ActiveRecord
- IntermediateKotlinNull safety · coroutines · Flow · Java interop
Systems & Architecture
Cloud & DevOps
- IntermediateDevOps EngineeringCI/CD · containers · IaC · release automation
- AllAWSCore services · IAM · VPC · well-architected
- AllAzureCore services · Entra ID · networking · governance
- AdvancedKubernetesPods · services · ingress · operators · scaling
- IntermediateDockerImages · layers · networking · compose
- IntermediateTerraformIaC · state · modules · providers · drift
- AdvancedSite Reliability EngineeringSLO/SLI · incident response · observability · toil
Data & ML
- AllSQLJoins · window functions · indexes · normalization
- IntermediateNoSQLMongoDB · DynamoDB · access patterns
- AdvancedData EngineeringETL · Spark · streaming · warehousing
- IntermediateML BasicsLinear / tree models · evaluation · features
- IntermediateGenAI / LLM EngineeringLLMs · prompting · RAG · evals · agents
- AllData AnalysisEDA · statistics · visualisation · SQL analytics
- AdvancedApache SparkRDD/DataFrame · transformations · tuning · shuffle
- AdvancedApache KafkaTopics · partitions · consumers · exactly-once
- IntermediateMongoDBDocuments · indexes · aggregation · sharding
- IntermediateRedisData structures · caching · persistence · pub/sub