1 to 25 of 30 Jest Jobs in London

complex bugs, identifying root causes, andimplementing robust solutions for production issues. Champion and implement frontend best practices in areas such as performance optimization, code quality, testing (React Testing Library, Jest, etc.), accessibility, and maintainability. Drive improvements and innovation in ourfrontend architecture, tooling (NPM, Webpack, Vite), and development processes. Technologies We Use Languages & Frameworks: JavaScript (ES6+), TypeScript, React, Next.js, Redux, HTML5 … CSS3/SCSS Testing: React Testing Library, Jest, Cypress (or similar) Build & Tooling: NPM, Webpack, Vite (or similar modernbundlers), Babel DevOps & Tools: AWS (S3, CloudFront, etc.), GitlabCI/CD, Git Backend Interaction: RESTful APIs (from Grails/Java services) Qualifications Must haves: 5-7+ years of proven track record in frontend development, with a strongportfolio of building complex, scalable … web applications using JavaScript, CSS, and HTML. Expert-level experience with React, Next.js, and state management libraries like Redux. Proficient with React Testing Library, Jest, or similarfrontend testing frameworks. Demonstrated ability to lead technical design discussions, collaborate effectively with UI/UX, andtranslate complex requirements into technically feasible and elegant designs. Deep experience setting up, configuring, and optimizing modern JavaScript More ❯

regulated environments such as banking, fintech, or insurance. Experience contributing to or establishing a Centre of Excellence in a financial services context. Strong knowledge of frontend testing frameworks (e.g., Jest, Cypress). Excellent communication skills and ability to collaborate across multidisciplinary teams. Experience working within Agile delivery frameworks and high-accountability environments. Desirable Attributes Experience with design systems and component More ❯

Code Quality: Participate in code reviews and contribute to the development of best practices to enhance code quality and maintainability. Implement Testing Strategies: Utilize testing frameworks like Playwright and Jest to ensure the reliability and stability of the codebase through rigorous testing practices. Stay Current with Technologies: Continuously explore and implement cutting-edge technologies, frameworks, and tools to enhance our … create visually appealing interfaces. Developer-Centered Approach: Experience in building UIs for a developer, DevOps or SRE audience. Testing Frameworks: Proficiency in using testing frameworks such as Playwright and Jest to ensure high code quality and user experience. Version Control: Proficient in using Git for version control and collaboration on code repositories. Problem-Solving Skills : Strong analytical and problem-solving More ❯

GraphQL . Understanding of event-driven architectures and message queues (e.g., Kafka , RabbitMQ ). Knowledge of performance optimization tools and strategies for backend systems. Familiarity with testing frameworks (e.g., Jest , Cypress , Playwright ) for unit, integration, and end-to-end testing. Familiarity with CI/CD pipelines and DevOps tools (e.g., GitHub Actions , Docker , Kubernetes ). Exposure to cloud platforms such More ❯

ES6+), Node.js, and React, with a solid understanding of their ecosystems. Experience with modern development tools and practices, such as Git, CI/CD pipelines, automated testing frameworks (e.g., Jest, Mocha), and containerisation technologies (e.g., Docker). Knowledge of RESTful API design and development, and familiarity with web services architecture. Ability to write efficient, secure, well-documented, and clean JavaScript More ❯

requirements. Integrate and optimize REST APIs for data retrieval and manipulation. Develop reusable components and ensure consistency across applications. Write and maintain high-quality, testable code with tools like Jest and Playwright. Perform data wrangling tasks and contribute to data analysis processes where necessary. Troubleshoot, debug, and enhance existing applications to improve performance and reliability. Why Join Us? This role … that values innovation, learning, and collaboration. Required Skills & Experience Web Development: Proficient in React and TypeScript. Data Visualization: Experience with libraries such as Highcharts and D3.js. Testing: Familiarity with Jest and Playwright or similar testing frameworks. REST APIs: Strong understanding of integrating and working with RESTful services. Data Skills: Experience in data wrangling/analysis (e.g., using SQL or Python More ❯

and JavaScript Node.js React Docker and containerized development workflows Git and version control NoSQL databases - MongoDB and Redis AWS services - EC2, Lambda, S3, and CloudWatch RESTful APIs Testing frameworks - Jest , Mocha , or similar CI/CD pipelines Start-up background Salary They offer a strong all round package with a base salary of up to £60,000 with some added More ❯

and JavaScript Node.js React Docker and containerized development workflows Git and version control NoSQL databases - MongoDB and Redis AWS services - EC2, Lambda, S3, and CloudWatch RESTful APIs Testing frameworks - Jest , Mocha , or similar CI/CD pipelines Start up background Salary They offer a base salary of £50,000 and £60,000 Equity. Location This client has an office in More ❯

Actions), Observability (AWS, Grafana). Development tools: GitHub, Jira, Notion, ChatGPT, Gemini, LangChain, AI-native IDE's (Cursor, JetBrains), LLM-powered internal tools. Test automation: Cypress (E2E), Postman (API), Jest (frontend unit), PHPUnit (backend unit), JUnit (Android), XCTest (iOS). WHAT WE OFFER YOU A front-row seat in a fast scaling, early stage startup. Working on cutting edge problems More ❯

diverse group of people with different areas of expertise. You are comfortably organized amongst chaos. Be familiar with our tech stack: TypeScript, React, styled-component Python PostgreSQL, BigQuery, MySQL Jest, React Testing Library, Cypress, pytes AWS, GCP Kubernetes, Docker, Terraform, GitHub, CircleCI Next.js (Preferred) AR/VR (Preferred) Embrace differences and know that when we can be ourselves at work More ❯

AWS, Grafana), OpenAI in Azure. Development tools: GitHub, Jira, Notion, ChatGPT, Gemini, LangChain, AI-native IDE's (Cursor, JetBrains), LLM-powered internal tools. Test automation: Cypress (E2E), Postman (API), Jest (frontend unit), PHPUnit (backend unit), JUnit (Android), XCTest (iOS). WHAT WE OFFER YOU A front-row seat in a fast scaling, early stage startup. Opportunity to define the ML More ❯

next generation of microservices platforms. - Continuous learning, we believe, ongoing training is key to success. Our Tech Stack - Frontend: React - Backend: Nest.js, Python/fastapi, LangChain Test Automation: Pact, Jest, Cypress, and Pytest (including AI test automation) - Infrastructure: AWS ECS, PostgreSQL, Kafka (migrating from RabbitMQ) - Infrastructure as Code: Terraform (using native AWS services where possible) - CI/CD: GitHub-based More ❯

Strong experience in test automation and functional testing Expertise in Playwright with JavaScript/TypeScript and C# Experience testing SPAs, APIs (Playwright API, Postman, REST Assured,) Familiarity with Mocha, Jest, BDD tools like Cucumber (preferred) CI/CD knowledge (Git, Jenkins, Azure DevOps) What's on Offer Varied, engaging work with new challenges daily Projects across public and private sectors More ❯

/React Native, Python (Django, Django REST framework, pandas) Docker, Postgresql, Airflow, Redis, Kafka CircleCI & Terraform AWS services (RDS, Elasticache, EC2, ECS, Fargate, Lambda, Batch, etc.) JIRA, Sentry, Mixpanel Jest, react-testing-library, Cypress Leadership/mentoring Mobile-first and PWA Problem-solving Senior Front End Engineer rewards: A base salary of circa 65-70k L&D budget Stock More ❯

field; with 3+ years industry experience or equivalent combination of education, training, and experience; Good to have: • Experience with Next.js • Experience with Redis/Memcached • Experience with PHPUnit, mocha, jest, or similar ; • Experience in server technologies, specifically AWS; • Experience in Docker applications will be a plus; • Familiarity with open-source software a plus; • Familiarity with JIRA, Jenkins, Elasticsearch, Grafana, Kibana More ❯

projects. Technology We're pragmatic about our technology choices. These are some of the things we use at the moment: TypeScript, React, styled-components Python, NodeJS ️ PostgreSQL, BigQuery, MySQL Jest, React Testing Library, Cypress, pytest ️ AWS, GCP Kubernetes, Docker, Terraform, GitHub, CircleCI How we expect you to work ️ We expect you to work in these ways, as well as encouraging More ❯

data-driven approach. Proficiency in a recognised programming language (e.g., JavaScript, Python, Java). Preferred Skills: TypeScript, NextJS/React, AWS (Lambda/Step Functions, Postgres/Dynamo, CDK), Jest, Playwright. My client offers a competitive salary, a share incentive scheme, private health insurance, and a flexible hybrid working environment with a "4 weeks from anywhere" policy. They foster a More ❯

types! We also use d3, Formik, and Zustand to build out the products, and styled-components and tailwind to make them pretty. And then we test them with vitest, jest, and playwright. If you're also interested in the backends, here's some other tech we use: PHP, NodeJS, Docker, Elastic, Redis, and all the services offered by AWS. We More ❯

environment (Scrum/Kanban). Bonus Points: Experience with Redux, GraphQL, or other state management libraries. Background working with SaaS or FinTech applications. Familiarity with mobile testing frameworks like Jest or Detox. Experience with cloud services and mobile deployment pipelines. More ❯

ecosystem differences. Familiarity with RESTful APIs and mobile libraries for networking. Strong proficiency in JavaScript, including DOM manipulation and the JavaScript object model. Experience with automated testing suites, like Jest or Mocha. Excellent problem-solving skills and the ability to think algorithmically. Experience with cloud message APIs and usage of push notifications. Knowledge of CI/CD pipelines, code signing More ❯

Senior React Native Developer opportunity. Interviews are taking place shortly! Keywords: Senior React Native Developer, Mobile App Development, UI/UX, iOS, Android, Redux, RESTful APIs, GitHub, MSSQL, Mocha, Jest, Clean Code, Agile, FinTech, Hybrid Working, London, App Store, Google Play, Mobile App Launch Established in Didsbury, Connexa Technology Ltd is becoming one of the UK's fastest growing IT More ❯

Senior React Native Developer opportunity. Interviews are taking place shortly! Keywords: Senior React Native Developer, Mobile App Development, UI/UX, iOS, Android, Redux, RESTful APIs, GitHub, MSSQL, Mocha, Jest, Clean Code, Agile, FinTech, Hybrid Working, London, App Store, Google Play, Mobile App Launch Established in Didsbury, Connexa Technology Ltd is becoming one of the UK's fastest growing IT More ❯

types! We also use d3, Formik, and Zustand to build out the products, and styled-components and tailwind to make them pretty. And then we test them with vitest, jest, and playwright. If you're also interested in the backends, here's some other tech we use: PHP, NodeJS, Docker, Elastic, Redis, and all the services offered by AWS. We More ❯

party services. Understanding of software development principles and best practices. Experience with version control systems (Git). Experience with cloud platforms (AWS) is a plus. Experience with testing frameworks (Jest) is a plus. Excellent problem solving and debugging skills. Strong communication and collaboration skills. Ability to work independently and as part of a team. Experience in the property management or More ❯

ecosystem differences. Familiarity with RESTful APIs and mobile libraries for networking. Strong proficiency in JavaScript, including DOM manipulation and the JavaScript object model. Experience with automated testing suites, like Jest or Mocha. Excellent problem-solving skills and the ability to think algorithmically. Experience with cloud message APIs and usage of push notifications. Knowledge of CI/CD pipelines, code signing More ❯