Tracks
Every language, framework, database and cross-cutting skill we grade, and how much of each is ready.
Languages
- C#Live
Types, collections, LINQ, async and the language features .NET interviewers probe first.
120 questions - JavaBeta
Core language, collections, generics, streams, concurrency primitives and the JVM basics.
80 questions - PythonBeta
The Python interviewers expect: data model, comprehensions, generators, typing and the standard library.
80 questions - JavaScriptBeta
Closures, the event loop, prototypes, promises and the quirks that trip people up in front-end loops.
80 questions - TypeScriptBeta
The type system beyond annotations: narrowing, generics, utility types, and how to model real domains.
80 questions - GoComing soon
Goroutines, channels, interfaces, error handling and the idioms Go reviewers care about.
0 questions - PHPComing soon
Modern PHP: types, OOP, Composer, error handling and the runtime model.
0 questions - RubyComing soon
Blocks, modules, metaprogramming basics and idiomatic Ruby.
0 questions - RustComing soon
Ownership, borrowing, lifetimes, traits and error handling without a garbage collector.
0 questions - C++Coming soon
Memory, RAII, templates, the STL and modern C++ features.
0 questions - KotlinComing soon
Null safety, coroutines, data classes and Kotlin idioms on the JVM and Android.
0 questions - SwiftComing soon
Optionals, value types, protocols and concurrency in Swift.
0 questions - SQL fundamentalsLive
Engine-agnostic SQL: the joins, aggregates, subqueries and set logic every data interview starts with.
120 questions
Frameworks
Dependency injection, the middleware pipeline, EF Core, auth and the questions every .NET backend loop asks.
120 questions- Spring BootBeta
Beans, auto-configuration, Spring MVC, Data JPA, security and testing.
80 questions - DjangoComing soon
ORM, migrations, views, middleware, forms and Django REST Framework.
0 questions - FastAPIComing soon
Pydantic models, dependency injection, async endpoints and OpenAPI.
0 questions - Node.jsComing soon
The runtime: event loop, streams, modules, process model and performance.
0 questions - ExpressComing soon
Routing, middleware, error handling and structuring an Express API.
0 questions - NestJSComing soon
Modules, providers, DI, pipes, guards, interceptors and testing in Nest.
0 questions - ReactBeta
Rendering, hooks, state, effects, performance and the mental model behind them.
80 questions - Next.jsComing soon
App Router, server components, rendering modes, caching and data fetching.
0 questions - VueComing soon
Reactivity, the Composition API, components, routing and state.
0 questions - AngularComing soon
Components, DI, RxJS, change detection, forms and routing.
0 questions - LaravelComing soon
Eloquent, routing, middleware, queues and the service container.
0 questions - Ruby on RailsComing soon
ActiveRecord, conventions, controllers, callbacks and background jobs.
0 questions - FlutterComing soon
Widgets, state management, layout, navigation and platform channels.
0 questions - React NativeComing soon
The bridge, native modules, navigation, styling and performance on mobile.
0 questions
Databases
T-SQL, indexing, execution plans, isolation and the tuning questions SQL Server shops ask.
120 questions- PostgreSQLLive
Joins, window functions, EXPLAIN, MVCC, indexes and PostgreSQL-specific features.
120 questions - MySQLBeta
InnoDB, indexing, EXPLAIN, isolation levels and MySQL specifics.
80 questions - Oracle (PL/SQL)Coming soon
PL/SQL, packages, cursors, optimizer hints and Oracle-specific SQL.
0 questions - SQLiteComing soon
The embedded database: typing, transactions, indexes, WAL and its limits.
0 questions - MongoDBComing soon
Document modelling, the aggregation pipeline, indexes, transactions and replication.
0 questions - RedisComing soon
Data structures, caching patterns, persistence, pub/sub and cluster.
0 questions - ElasticsearchComing soon
Inverted indexes, mappings, analyzers, queries, aggregations and cluster basics.
0 questions - CassandraComing soon
Partitioning, consistency levels, query-first modelling and compaction.
0 questions
Cross-cutting
- Data structures & algorithmsComing soon
Complexity, arrays, hashing, trees, graphs, sorting and the patterns behind coding rounds.
0 questions - System designComing soon
Scaling, caching, queues, consistency, storage choices and the trade-offs behind them.
0 questions - REST & API designComing soon
Resources, verbs, status codes, versioning, pagination, idempotency and errors.
0 questions - GitComing soon
Branching, merging, rebasing, history surgery and collaboration workflows.
0 questions - Docker & KubernetesComing soon
Images, layers, networking, volumes, then pods, services, deployments and scaling.
0 questions - Testing & TDDComing soon
The test pyramid, TDD, mocks vs fakes, flaky tests and what to test at each layer.
0 questions - Security / OWASP Top 10Coming soon
Injection, auth failures, XSS, CSRF, secrets, crypto basics and secure defaults.
0 questions - Concurrency & threadingComing soon
Threads vs async, races, locks, deadlocks, memory models and safe patterns.
0 questions - Message queuesComing soon
Brokers, delivery guarantees, ordering, idempotency, dead letters and event-driven design.
0 questions - Cloud fundamentals (AWS/Azure)Coming soon
Compute, storage, networking, IAM, managed databases, serverless and cost.
0 questions