Expert tutorials, cheat sheets & deep-dives on Java, Spring, DevOps, Cloud, MSSQL, AI/ML and more
593 commands across Windows CMD, PowerShell, Git, MSSQL, JBoss, AWS, TeamCity, Docker, IIS & more. Instant search + copy buttons.
14 ready-to-run T-SQL scripts — JOINs, window functions, security, In-Memory OLTP, CDC, partitioning and more.
Download & install SQL Server Developer Edition (free), SSMS and Azure Data Studio — step by step with post-install config.
JSON Comparator, JWT Decoder, Regex Tester, Docker Compose Generator, Base64, CRON Builder, REST API Tester and more.
Autonomous agents reshaping enterprise software development
AI NewsGPT-5 enterprise features and deployment strategies
AI NewsMulti-modal AI capabilities and developer integration
AI NewsState of AI-assisted coding in 2026
AI NewsEmerging AI-powered attack vectors and defences
AI NewsRunning AI inference at the edge without the cloud
Master functional programming with lambdas, streams and optionals
Java 11HTTP client, var in lambdas, String methods and module system
OpenJDKEssential tips, tools and best practices for OpenJDK development
Java HomeComplete roadmap from basics to advanced Java architecture
Q&AMost-asked Java interview questions with detailed answers
FunProgramming humour for every Java developer's day
AlgorithmsBig O analysis for arrays, trees and sorting algorithms with Java examples.
ConcurrencyJava concurrency primitives with real-world producer-consumer examples.
SecurityAES encryption, RSA signing, MessageDigest and JSSE complete Java crypto reference.
HistoryEvery major Java release from 1996 to today. Ideal for interview prep.
Data StructuresImplement O(1) LRU cache with LinkedHashMap and JDK 21 SequencedMap.
ArchitectureRecords, sealed classes and value objects vs classic OOP patterns in Java.
AIIntegrate OpenAI, Ollama and vector stores into Spring Boot with Spring AI.
JVMPractical JVM language comparison for backend, data and scripting use cases.
JDKChoose the right JDK distribution for production workloads in 2026.
Data StructuresHow TreeMap uses Red-Black trees internally with insertion and rotation visuals.
CareerJava job market, salary ranges, certifications and learning roadmap for 2026.
BasicsClear comparison with code examples - when to use constructors vs factory methods.
BasicsScope, lifetime, default values and heap vs stack explained with examples.
ModulesJava Platform Module System from Java 9 - module-info.java, exports and requires.
ToolsKill Java processes by PID, port or name using taskkill and jps commands.
SecuritySplunk, Elastic SIEM, QRadar, Microsoft Sentinel and open-source alternatives.
JBossDeploy, configure and tune JBoss/WildFly - datasources, JNDI and clustering.
OpenJDKOfficial docs, JEPs, mailing lists and conference talks for OpenJDK learning.
DockerPull, run and customise AdoptOpenJDK containers for development and production.
HTTPjava.net.http.HttpClient - sync/async requests, WebSocket and multipart uploads.
ExceptionsChecked vs unchecked, exception hierarchies, custom exceptions and best practices.
IDEEclipse IDE installation, plugins, shortcuts and Java debugging tips for 2020 and beyond.
Auto-configuration, starters, actuator and production patterns
MicroservicesService discovery, circuit breaker, API gateway and more
SecurityJWT auth, OAuth2, CSRF protection and role-based access
Data JPARepositories, query methods, pagination and N+1 fixes
AdvancedEvent-driven, caching, async and transaction management
AICompare Spring AI and LangChain4j for building LLM-powered Java applications.
PerformanceReduce startup time with Spring AOT, GraalVM native images and build-time hints.
Configapplication.yml, @ConfigurationProperties, profiles and Kubernetes ConfigMap.
MessagingRabbitMQ, Kafka and Spring Integration event-driven patterns with code examples.
ComparisonStartup time, memory footprint, ecosystem and developer experience compared.
ReactiveMono, Flux, backpressure, R2DBC reactive database and WebClient patterns.
Mavenmvn install:install-file with groupId, artifactId and version - with examples.
14 script files — all T-SQL topics from JOINs to In-Memory OLTP
SQL ServerFree Developer Edition, step-by-step setup and post-install config
HibernateEntity mapping, associations, caching and enterprise patterns
PerformanceN+1 fixes, batch fetching, HikariCP and second-level cache
HibernateFirst-level, second-level and query cache deep dive
HibernateRepository pattern, auditing, multi-tenancy and optimistic locking
NoSQLDeep-dive comparison — when to choose each, benchmarks
DistributedConflict-free replicated data types for real-time collaboration
MigrationFlyway, Liquibase and zero-downtime schema migrations
RoadmapFrom beginner to architect — the structured learning path
TutorialComplete hands-on introduction to Hibernate ORM
Practical guide: pipelines, automation, Docker and Kubernetes
MiddlewareStep-by-step migration guide with configuration and troubleshooting
DockerContainers, images, Compose and production deployment patterns
K8sPods, services, deployments, Helm charts and monitoring
Cheat SheetTeamCity REST API, AWS CLI, Docker — copy-paste command reference
ToolsThe best free tools for productivity, debugging, API testing and monitoring.
Instance types, AMIs, Auto Scaling, Spot instances and placement groups
LambdaRuntimes, triggers, cold starts, Provisioned Concurrency and DLQ
EKSCluster creation, managed node groups, Fargate, IRSA and load balancer
Step FunctionsState machine orchestration for serverless workflows with error handling
EventBridgeEvent-driven architecture, event buses, rules, Pipes and Scheduler
Cost15 strategies: Savings Plans, Spot, S3 lifecycle, VPC endpoints and tagging
CloudFront CDNComplete AWS CloudFront guide: distributions, cache behaviors, TTL settings, Lambda@Edge, origin group...
EC2 Spot InstancesComplete guide to AWS EC2 Spot Instances: pricing model, Spot Fleet, interruption handling, Spot with ...
Lambda Cold StartsEliminate AWS Lambda cold starts with SnapStart, provisioned concurrency, and code optimization. Compl...
CodePipeline and C...Complete guide to AWS CodePipeline and CodeBuild: building CI/CD pipelines, buildspec.yml, multi-stage...
S3 Lifecycle RulesComplete guide to AWS S3 lifecycle rules, cross-region replication, Intelligent-Tiering storage class,...
Secrets ManagerComplete AWS Secrets Manager guide: storing secrets, automatic rotation with Lambda, cross-account acc...
SSM Parameter Stor...Complete AWS Systems Manager guide: Parameter Store for config and secrets, Session Manager for SSH-fr...
Terraform GuideComplete Terraform on AWS guide: providers, modules, state management with S3 backend, workspaces, Ter...
AmplifyComplete AWS Amplify guide: CLI setup, Gen 2 TypeScript backend, Cognito auth, AppSync GraphQL, S3 sto...
AppSync GraphQLComplete AWS AppSync guide: GraphQL schema design, DynamoDB resolvers, real-time subscriptions, authen...
Athena and GlueComplete AWS Athena and Glue guide: serverless SQL on S3, Parquet optimization, Glue ETL jobs, Data Ca...
Aurora ServerlessComplete AWS Aurora Serverless v2 guide: ACU scaling, Data API, RDS Proxy, zero-ETL Redshift integrati...
EKS FargateComplete AWS EKS Fargate guide: Fargate profiles, pod scheduling, networking with VPC CNI, ALB Ingress...
KinesisComplete AWS Kinesis guide: Data Streams shards and consumers, Firehose delivery, Kinesis Analytics wi...
Organizations and ...Complete AWS Organizations and Control Tower guide: OUs, SCPs, landing zones, guardrails, Account Fact...
SageMakerComplete AWS SageMaker guide: training jobs, model deployment, SageMaker Pipelines, Feature Store, mod...
Transit GatewayComplete AWS Transit Gateway guide: multi-VPC hub-and-spoke architecture, VPN attachments, Direct Conn...
WAF and ShieldComplete AWS WAF and Shield guide: Web ACLs, managed rules, rate limiting, DDoS protection, Shield Adv...
Auto ScalingComplete guide to AWS Auto Scaling: EC2 Auto Scaling Groups, target tracking, step scaling, scheduled ...
BackupComplete guide to AWS Backup: backup plans, vaults, retention policies, cross-region and cross-account...
Config and Securit...Complete guide to AWS Config rules, conformance packs, Security Hub standards (CIS, PCI-DSS), automate...
Direct ConnectDeep dive into AWS Direct Connect: connection types, virtual interfaces, Direct Connect Gateway, LAG, ...
ECS vs EKS vs LambdaAWS ECS vs EKS vs Lambda: a complete decision guide covering architecture, cost, use cases, migration ...
BedrockComplete AWS Bedrock guide: invoke Claude, Titan, Llama and Mistral models, build RAG with Knowledge B...
Lake FormationComplete AWS Lake Formation guide: set up a secure data lake in hours. Covers S3 registration, column/...
MSKComplete AWS MSK guide: Standard vs Serverless clusters, Kafka producer/consumer code in Java and Pyth...
OpenSearch ServiceComplete AWS OpenSearch Service guide: domain setup, index management, REST API queries, Python and Ja...
RDS ProxyDeep-dive into AWS RDS Proxy — how connection multiplexing works, Lambda integration, IAM authenticati...
EFS and FSxComplete guide to AWS EFS and FSx: EFS performance modes, throughput modes, ECS/EKS integration, FSx f...
Glue ETLComplete AWS Glue ETL guide: Data Catalog, Crawlers, PySpark jobs, DynamicFrames, job bookmarks, Glue ...
Lambda LayersComplete guide to AWS Lambda Layers: directory structure, creating Python/Node.js/Java layers, publish...
SNS to SQS FanMaster the AWS SNS to SQS fan-out pattern: subscription filter policies, Lambda consumers, DLQs, cross...
VPC ConnectivityMaster every AWS VPC connectivity option: VPC Peering, Transit Gateway, PrivateLink, Site-to-Site VPN,...
CloudTrailMaster AWS CloudTrail: event types, trail setup, Athena queries, CloudTrail Insights, real-time alerti...
ECRComplete guide to AWS ECR: creating repositories, Docker auth, CI/CD integration, image scanning with ...
Elastic BeanstalkComplete guide to AWS Elastic Beanstalk: EB CLI, .ebextensions, deployment policies (rolling, immutabl...
CodeDeployComplete guide to AWS CodeDeploy: blue-green, canary, linear, and rolling deployment strategies for EC...
DynamoDB Streams a...Master DynamoDB Streams with Lambda: stream view types, shard architecture, event source mapping, CDC ...
GravitonComplete guide to AWS Graviton processors: Graviton1 through Graviton4, instance families (C7g, M7g, R...
GuardDutyComplete AWS GuardDuty guide: threat categories, data sources, finding anatomy, automated incident res...
IoT CoreComplete AWS IoT Core guide: device provisioning, MQTT, Rules Engine, Device Shadow, IoT Jobs, Greengr...
RekognitionComplete AWS Rekognition guide: image labels, face recognition, content moderation, custom labels, vid...
WellComplete guide to the AWS Well-Architected Framework covering all 6 pillars: Operational Excellence, S...
Architecture, control plane, kubectl, namespaces and the declarative model
HelmChart structure, template syntax, values override and custom chart publishing
IstioTraffic management, mTLS, canary routing, Kiali and Jaeger tracing
KarpenterJust-in-time nodes, NodePool CRD, spot fallback and cost consolidation
SecurityPod Security Standards, Kyverno, RBAC, image scanning and audit logging
FluxGitOps principles, Flux v2, HelmRelease, image automation and multi-env setup
Pydantic, async endpoints, JWT auth, SQLAlchemy integration and Docker deploy
Django RESTViewSets, JWT auth, serializers, filtering, pagination and N+1 optimization
Pydantic V2BaseModel, field validators, computed fields, pydantic-settings and V1→V2 migration
CeleryRedis broker, Beat scheduler, retry backoff, Flower monitoring and task canvas
Boto3S3, EC2, Lambda, DynamoDB, SQS, Secrets Manager and paginator patterns
PerformancecProfile, NumPy vectorization, multiprocessing vs asyncio and lru_cache
DataclassesComplete Python dataclasses guide: @dataclass decorator, field(), frozen and slotted dataclasses, inhe...
useState, useEffect, useRef, useMemo, useCallback and rules of hooks
Next.jsApp Router, Server Components, Server Actions, ISR and Vercel deployment
StateRedux Toolkit, Zustand, TanStack Query and when to use each option
TypeScriptComponent typing, generics, discriminated unions and strict null checks
TestingQueries, user-event, MSW mocking, renderHook and CI integration
PerformanceReact.memo, useMemo, code splitting, virtualization and Profiler
EC2, ECS, RDS, Lambda and best practice architecture
AzureApp Service, Azure SQL, Functions and DevOps pipelines
GCPGKE, BigQuery, Cloud Run and Pub/Sub overview
ServerlessFunctions-as-a-service, event-driven patterns and cost optimisation
OWASP Top 10, XSS, SQL injection, CSRF prevention
SpringJWT, OAuth2, method security and security testing
SQL ServerRLS, Dynamic Data Masking, audit, EXECUTE AS patterns
Web SecurityReflected XSS, IDOR and SSRF attack patterns, PoC examples and remediation strategies.
End-to-end testing, selectors, custom commands and CI integration
SeleniumPage object model, waits, cross-browser testing and reporting
FrameworksScalable framework design with TestNG, JUnit 5 and Allure
ToolPaste HTML → instantly get selectors, it-blocks and assertions
PerformanceJMeter, Gatling and k6 — performance testing strategies
CypressFull Cypress course from setup to CI/CD - commands, fixtures and reporters.
CI/CDCompare parallelisation, cost, flake detection and reporting between the two.
SeleniumRecord, edit and replay Selenium tests without code - setup and export guide.
ExceptionsDiagnose and fix click interceptions caused by overlays, modals and fixed headers.
ExceptionsHandle invisible elements with explicit waits, scrollIntoView and JavaScript clicks.
ExceptionsFix Select class errors, stale dropdowns and disabled elements in Selenium.
ExceptionsRoot causes and fixes for read-only, disabled and non-interactable element errors.
ExceptionsDebug malformed CSS and XPath selectors - common patterns and validation tools.
ExceptionsHandle JS errors thrown during executeScript calls and async JavaScript execution.
ExceptionsFix Actions chain failures when elements are off-screen or in scrollable containers.
ExceptionsMaster explicit waits, dynamic locators and XPath axes to eliminate errors.
ExceptionsRe-locate elements after DOM refreshes - page object patterns and retry strategies.
ExceptionsTune implicit/explicit timeouts and diagnose slow AJAX and SPA applications.
DebuggingHandle browser popups, downloads, SSL errors and notification dialogs.
ExceptionsFix Select class errors when the target is not a native HTML select element.
ExceptionsAccept, dismiss and read text from JS alert(), confirm() and prompt() dialogs.
SeleniumImplicit, explicit and fluent waits - when to use each and common anti-patterns.
Routes, upstreams, plugins, authentication and rate limiting
APISIXWriting custom Lua plugins for traffic control
ToolBuild APISIX configs visually — get Admin API JSON instantly
ToolBrowser-based HTTP client — Postman-lite, no install
APISIXRoutes, upstreams, plugins, Admin API and dashboard - complete APISIX reference.
ComparisonAPI gateway comparison: performance, plugin ecosystem, K8s ingress and pricing.
API DesignDesign-first vs code-first APIs, OpenAPI 3.1, contract testing and team workflows.
OpenAPIOpenAPI 3.1 spec, Swagger UI, code generation and automated contract testing.
Topics, partitions, consumer groups and offset management
Spring KafkaProducer/consumer patterns, error handling and retry
StreamsStateful processing, windowing and real-time aggregations
Kafka OpsConsumer lag, partition rebalance, broker failure recovery, monitoring and tuning for Kafka.
Roadmap from Python basics to production ML models
Deep LearningNeural networks, TensorFlow, PyTorch and transfer learning
NLPIntegrating OpenAI, Gemini and local models in Java apps
MLOpsCI/CD for ML, model versioning and monitoring in production
GuideMaster prompt engineering: zero-shot, few-shot, chain-of-thought, ReAct, system prompts, temperature t...
AI SkillsPrompt engineering, RAG, agents, fine-tuning and MLOps - the essential AI stack.
FrameworksSide-by-side comparison of the top 4 AI agent frameworks with use cases.
ProjectBuild a full-stack image captioning app using Spring AI and a vision LLM.
593 commands — Windows, PS, Git, MSSQL, JBoss, AWS, Docker, IIS
Online ToolCompare, validate, beautify and diff JSON documents online
Online ToolDecode any JWT, verify expiry and encode new tokens
Online ToolLive match highlighting, groups and pattern library
Online ToolValidate, beautify, minify and view document tree
Online ToolVisual multi-service docker-compose.yml builder
Online ToolText, files and inline image preview
Online ToolBuild cron visually with human-readable description
Online ToolVisual schema designer → Mongoose + validation JSON
Online ToolConvert SQL queries to aggregation pipeline and back
Java, Spring Boot, DevOps, Cloud and AI/ML — practical tutorials, live coding and career guidance.