# Skills Tests for React, Python, SQL and More > Skills tests and evidence guides for tech skills: what competence looks like, what counts as proof and how adaptive assessments and live sessions test it. Source: https://getlemma.io/skills Each page in this directory is a skills test guide for one skill: what competence looks like, what counts as evidence for it, and how Lemma tests it through adaptive assessments, live sessions and connected work. ## What every skill page covers ### What competence looks like The decisions and habits that separate someone who uses the skill daily from someone who read about it. ### What counts as evidence Concrete artefacts for that skill: live sessions, assessment results and work connected from GitHub, Figma or Vercel. ### How it is assessed How Lemma tests the skill and how the evidence adds up to a score you can share on your Skills Passport. ## Frontend Interfaces people use in the browser, and the languages and frameworks behind them. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Frontend evidence 6 skills - Live session - Adaptive assessment - AI tutor practice - GitHub connector - Vercel connector - [### React Show how you structure components, manage state and keep renders fast, with evidence behind it.](https://getlemma.io/skills/react) - [### JavaScript Evidence that you understand how JavaScript runs, not just how to write its syntax.](https://getlemma.io/skills/javascript) - [### TypeScript Show that your types catch real bugs instead of just silencing the compiler.](https://getlemma.io/skills/typescript) - [### Next.js Evidence for rendering, routing and caching decisions in Next.js, backed by deployed work.](https://getlemma.io/skills/nextjs) - [### Vue.js Show how you use reactivity, composables and component design in Vue, with evidence.](https://getlemma.io/skills/vuejs) - [### Angular Evidence for structuring large Angular apps with services, RxJS and change detection.](https://getlemma.io/skills/angular) ## Mobile Native and cross-platform apps, from platform conventions to release builds. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Mobile evidence 3 skills - Live session - Adaptive assessment - AI tutor practice - GitHub connector - [### Swift Show how you build iOS apps in Swift and SwiftUI, from state to concurrency.](https://getlemma.io/skills/swift) - [### Kotlin Evidence for idiomatic Kotlin, coroutines and Android development, recorded from real work.](https://getlemma.io/skills/kotlin) - [### Mobile development Evidence for building mobile apps that work offline, stay fast and survive real devices.](https://getlemma.io/skills/mobile-development) ## Backend Services, APIs and the languages that run them under real load. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Backend evidence 6 skills - Live session - Adaptive assessment - AI tutor practice - GitHub connector - Vercel connector - [### GraphQL Show how you design GraphQL schemas and resolvers that stay fast and safe.](https://getlemma.io/skills/graphql) - [### Python Show how you write, debug and structure Python, not just that you once finished a course.](https://getlemma.io/skills/python) - [### Node.js Evidence of how you build and debug Node.js services, from the event loop to production errors.](https://getlemma.io/skills/nodejs) - [### Go Prove you write clear, concurrent Go services, with evidence from live code and connected repositories.](https://getlemma.io/skills/golang) - [### Rust Show that you work with the borrow checker rather than around it, through live code and connected crates.](https://getlemma.io/skills/rust) - [### Blockchain development Evidence of how you design, test and secure smart contracts, judged by practitioners in live sessions.](https://getlemma.io/skills/blockchain) ## Data and AI Querying, modelling and shipping data products and machine learning systems. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Data and AI evidence 4 skills - Live session - Adaptive assessment - AI tutor practice - GitHub connector - [### SQL Prove you can write correct, fast queries on real schemas, from joins to window functions and query plans.](https://getlemma.io/skills/sql) - [### Data analysis Evidence of how you frame questions, clean data and reach conclusions a decision-maker can rely on.](https://getlemma.io/skills/data-analysis) - [### Machine learning Show how you frame, train, evaluate and debug models, with evidence a practitioner has reviewed live.](https://getlemma.io/skills/machine-learning) - [### Data engineering Evidence that your pipelines are reliable, testable and recoverable, reviewed by practitioners in live sessions.](https://getlemma.io/skills/data-engineering) ## Infrastructure Cloud, containers, delivery pipelines, security and the architecture that ties them together. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Infrastructure evidence 6 skills - Live session - Adaptive assessment - AI tutor practice - GitHub connector - [### System design Show how you reason about scale, failure and trade-offs, in live design sessions reviewed by practitioners.](https://getlemma.io/skills/system-design) - [### AWS Evidence that you can design, secure and run workloads on AWS, not just name services.](https://getlemma.io/skills/aws) - [### Docker Show you can build small, secure images and debug containers when they misbehave.](https://getlemma.io/skills/docker) - [### DevOps Evidence of how you build pipelines, ship safely and keep systems observable.](https://getlemma.io/skills/devops) - [### Cloud architecture Show how you design cloud systems that scale, fail gracefully and stay affordable.](https://getlemma.io/skills/cloud-architecture) - [### Cybersecurity Evidence of how you find, prioritise and fix real security risks in systems and code.](https://getlemma.io/skills/cybersecurity) ## Design Interface, interaction and product design, judged by the work and the reasoning behind it. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Design evidence 3 skills - Live session - Adaptive assessment - AI tutor practice - Figma connector - [### Figma Show how you build files other designers and engineers can actually work in.](https://getlemma.io/skills/figma) - [### Product design Evidence of how you frame problems, make trade-offs and ship designs that hold up.](https://getlemma.io/skills/product-design) - [### UI/UX design Show that your interfaces are usable, accessible and consistent, not just attractive.](https://getlemma.io/skills/ui-ux-design) ## Product Deciding what to build and running the team process that ships it. ![Painting of a wide river winding through green woodland in golden light](https://cdn.sanity.io/images/islu4peo/production/99513c2c457dabadaeac637d82f799da033cd99e-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) Product evidence 2 skills - Live session - Adaptive assessment - AI tutor practice - [### Product management Evidence of how you prioritise, make calls with incomplete data and ship outcomes.](https://getlemma.io/skills/product-management) - [### Agile Show how you run iterative delivery in practice, not which ceremonies you can name.](https://getlemma.io/skills/agile) ## Interview questions by skill Real questions from junior to senior level, each with what a strong answer shows. Use them to prepare, or to run a fairer interview. - [SQL interview questions30](https://getlemma.io/skills/sql/interview-questions) - [Product management interview questions30](https://getlemma.io/skills/product-management/interview-questions) - [Python interview questions30](https://getlemma.io/skills/python/interview-questions) - [React interview questions30](https://getlemma.io/skills/react/interview-questions) - [System design interview questions30](https://getlemma.io/skills/system-design/interview-questions) - [JavaScript interview questions30](https://getlemma.io/skills/javascript/interview-questions) - [AWS interview questions30](https://getlemma.io/skills/aws/interview-questions) - [Node.js interview questions30](https://getlemma.io/skills/nodejs/interview-questions) - [TypeScript interview questions30](https://getlemma.io/skills/typescript/interview-questions) - [Docker interview questions30](https://getlemma.io/skills/docker/interview-questions) ![depresssed painting](https://cdn.sanity.io/images/islu4peo/production/a437bcfa740ce88acf14f88fd78d4b33a07c53e6-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) ## Skills tests: common questions ### What is a skills test? A skills test checks whether you can do a specific task, such as writing a SQL query or debugging a React component, rather than what you know about it in general. On Lemma it is an adaptive assessment of 15 to 25 questions, and harder questions count for more. ### How do I prove my technical skills to an employer? Combine evidence from more than one source: an adaptive skills test, live sessions where a practitioner sees how you work, and code or design files you built. On Lemma each piece is recorded against one skill with its date, and you share the record as a Skills Passport link. ### Which skills can I take a skills test in? Every skill in this directory, across frontend, mobile, backend, data and AI, infrastructure, design and product. Each skill page lists the topics its assessment covers and the other evidence that counts for it. ![Painting of an olive grove in soft sunlight with hills beyond](https://cdn.sanity.io/images/islu4peo/production/613eb3f93566423c9adf45246f2cf1a61437c04c-1680x1120.jpg?w=1080&fm=webp&q=68&fit=max) ## Start with the skill you use most. Lemma is in early access. Request an invite to begin building evidence for the skills in this directory.