1,176 to 1,200 of 1,322 ECMAScript Jobs in London

AI Software Developer (Python, JavaScript, ML) - London/Hybrid Day rate: £500 - £800 (inside IR35) Duration: 6 - 12 months Start: ASAP Hybrid: 3 days on site per week My client is looking for a Software Developer with AI, Python and JavaScript experience to join on a contract basis. As a Software Developer - AI, you will focus on the development and … AI driven software solutions, working within a dynamic team to enhance our digital products. You will be responsible for writing clean, efficient, and maintainable code, primarily in Python and JavaScript, while contributing to the successful deployment of Gen AI technologies that directly impact the company's customer experience (CX) vision. You will collaborate closely with other software engineers, product teams … input on sprint planning, task estimation, and iterative improvements Requirements: 3+ years of experience in software development, with exposure to AI or machine learning projects. Proficient in Python and JavaScript, ideally with hands-on experience in building Gen AI proof of concepts or integrating LLM APIs. Familiarity with AI platforms such as OpenAI, Anthropic, or Databricks. Strong understanding of AI More ❯

WordPress/PHP Developer £60,000 - £70,000 Hybrid - 3 days a week, central London (WordPress, PHP, JavaScript,) Would you like the opportunity to work with one of the leading worldwide SaaS organisation, working with WordPress, PHP and JavaScript? The Company A market leading SaaS company with a global presence, with high-end offices in central London You will be … work in the office three times a week with the rest of the team. Requirements: Strong WordPress/PHP experience - any framework (Symfony, Laravel, Zend, etc) Strong knowledge of JavaScript - (React, Vue.JS, Angular, etc) HTML/CSS Understanding of TDD and Gutenberg would be a bonus Experience of working in an agile environment This role requires you to work from … WordPress/PHP developer, this is a unique opportunity to join a market leading company with the added bonus of continuing to grow your skillset in PHP, WordPress and JavaScript, with an outstanding benefits package on offer. More ❯

WordPress/PHP Developer £60,000 - £70,000 Hybrid - 3 days a week, central London (WordPress, PHP, JavaScript,) Would you like the opportunity to work with one of the leading worldwide SaaS organisation, working with WordPress, PHP and JavaScript? The Company A market leading SaaS company with a global presence, with high-end offices in central London You will be … work in the office three times a week with the rest of the team. Requirements: Strong WordPress/PHP experience - any framework (Symfony, Laravel, Zend, etc) Strong knowledge of JavaScript - (React, Vue.JS, Angular, etc) HTML/CSS Understanding of TDD and Gutenberg would be a bonus Experience of working in an agile environment This role requires you to work from … WordPress/PHP developer, this is a unique opportunity to join a market leading company with the added bonus of continuing to grow your skillset in PHP, WordPress and JavaScript, with an outstanding benefits package on offer. More ❯

PHP Developer £60,000 - £70,000 Hybrid - 3 days a week, central London (WordPress, PHP, JavaScript,) Would you like the opportunity to work with one of the leading worldwide SaaS organisation, working with WordPress, PHP and JavaScript? The Company A market leading SaaS company with a global presence, with high-end offices in central London You will be joining an … a week with the rest of the team. Requirements: Strong PHP experience - any framework (Symfony, Laravel, Zend, etc) Have experience/interest in working with WordPress Strong knowledge of JavaScript - (React, Vue.JS, Angular, etc) HTML/CSS Understanding of TDD and Gutenberg would be a bonus Experience of working in an agile environment This role requires you to work from … As a PHP developer, this is a unique opportunity to join a market leading company with the added bonus of continuing to grow your skillset in PHP, WordPress and JavaScript, with an outstanding benefits package on offer. More ❯

PHP Developer £60,000 - £70,000 Hybrid - 3 days a week, central London (WordPress, PHP, JavaScript,) Would you like the opportunity to work with one of the leading worldwide SaaS organisation, working with WordPress, PHP and JavaScript? The Company A market leading SaaS company with a global presence, with high-end offices in central London You will be joining an … a week with the rest of the team. Requirements: Strong PHP experience - any framework (Symfony, Laravel, Zend, etc) Have experience/interest in working with WordPress Strong knowledge of JavaScript - (React, Vue.JS, Angular, etc) HTML/CSS Understanding of TDD and Gutenberg would be a bonus Experience of working in an agile environment This role requires you to work from … As a PHP developer, this is a unique opportunity to join a market leading company with the added bonus of continuing to grow your skillset in PHP, WordPress and JavaScript, with an outstanding benefits package on offer. More ❯

Trading UI Engineer – Front Office JavaScript, React, typescript, NodeJS, Tailwind, GraphQL, ApolloQL, Webpack, Cypress, HTML, CSS, REST, Data Visualisation, API. Real Time Trading Software, UI Development Perm Role – London – Onsite. £80000 - £100000 plus bonus Harrington Starr has partnered up with a Global Investment Bank in the City of London who are looking to hire a Senior UI Trading Software Developer … high profile role for a Multi Asset Trading Team within a Front Office environment. As the Senior Trading UI Developer, you will have extensive experience of working with the JavaScript Framework including ES7 and HTML and CSS. You will be working directly with Portfolio Managers, Sales Traders and Quants and end users where you will be responsible for specing out … designing and developing of UI screens for the users. This will require you to have client facing experience as well as low levy programming with JavaScript and React Development experience. Their systems cover all asset classes from FX, Fixed Income, Interest Rates and Commodities including derivative products although this knowledge is not essential but would be advantageous. The application is More ❯

Trading UI Engineer – Front Office JavaScript, React, typescript, NodeJS, Tailwind, GraphQL, ApolloQL, Webpack, Cypress, HTML, CSS, REST, Data Visualisation, API. Real Time Trading Software, UI Development Perm Role – London – Onsite. £80000 - £100000 plus bonus Harrington Starr has partnered up with a Global Investment Bank in the City of London who are looking to hire a Senior UI Trading Software Developer … high profile role for a Multi Asset Trading Team within a Front Office environment. As the Senior Trading UI Developer, you will have extensive experience of working with the JavaScript Framework including ES7 and HTML and CSS. You will be working directly with Portfolio Managers, Sales Traders and Quants and end users where you will be responsible for specing out … designing and developing of UI screens for the users. This will require you to have client facing experience as well as low levy programming with JavaScript and React Development experience. Their systems cover all asset classes from FX, Fixed Income, Interest Rates and Commodities including derivative products although this knowledge is not essential but would be advantageous. The application is More ❯

Trading UI Engineer – Front Office JavaScript, React, typescript, NodeJS, Tailwind, GraphQL, ApolloQL, Webpack, Cypress, HTML, CSS, REST, Data Visualisation, API. Real Time Trading Software, UI Development Perm Role – London – Onsite. £80000 - £100000 plus bonus Harrington Starr has partnered up with a Global Investment Bank in the City of London who are looking to hire a Senior UI Trading Software Developer … high profile role for a Multi Asset Trading Team within a Front Office environment. As the Senior Trading UI Developer, you will have extensive experience of working with the JavaScript Framework including ES7 and HTML and CSS. You will be working directly with Portfolio Managers, Sales Traders and Quants and end users where you will be responsible for specing out … designing and developing of UI screens for the users. This will require you to have client facing experience as well as low levy programming with JavaScript and React Development experience. Their systems cover all asset classes from FX, Fixed Income, Interest Rates and Commodities including derivative products although this knowledge is not essential but would be advantageous. The application is More ❯

Trading UI Engineer – Front Office JavaScript, React, typescript, NodeJS, Tailwind, GraphQL, ApolloQL, Webpack, Cypress, HTML, CSS, REST, Data Visualisation, API. Real Time Trading Software, UI Development Perm Role – London – Onsite. £80000 - £100000 plus bonus Harrington Starr has partnered up with a Global Investment Bank in the City of London who are looking to hire a Senior UI Trading Software Developer … high profile role for a Multi Asset Trading Team within a Front Office environment. As the Senior Trading UI Developer, you will have extensive experience of working with the JavaScript Framework including ES7 and HTML and CSS. You will be working directly with Portfolio Managers, Sales Traders and Quants and end users where you will be responsible for specing out … designing and developing of UI screens for the users. This will require you to have client facing experience as well as low levy programming with JavaScript and React Development experience. Their systems cover all asset classes from FX, Fixed Income, Interest Rates and Commodities including derivative products although this knowledge is not essential but would be advantageous. The application is More ❯

someone who has: 2-3+ years of experience working in a web development agency or in-house for a brand Experience developing Shopify themes Strong knowledge of modern JavaScript Ability to write well-structured, semantic, and accessible HTML Confidence writing framework-agnostic, performance-focused JavaScript Awareness of WCAG accessibility guidelines Solid understanding of front-end performance best practices Strong More ❯

someone who has: 2-3+ years of experience working in a web development agency or in-house for a brand Experience developing Shopify themes Strong knowledge of modern JavaScript Ability to write well-structured, semantic, and accessible HTML Confidence writing framework-agnostic, performance-focused JavaScript Awareness of WCAG accessibility guidelines Solid understanding of front-end performance best practices Strong More ❯

someone who has: 2-3+ years of experience working in a web development agency or in-house for a brand Experience developing Shopify themes Strong knowledge of modern JavaScript Ability to write well-structured, semantic, and accessible HTML Confidence writing framework-agnostic, performance-focused JavaScript Awareness of WCAG accessibility guidelines Solid understanding of front-end performance best practices Strong More ❯

someone who has: 2-3+ years of experience working in a web development agency or in-house for a brand Experience developing Shopify themes Strong knowledge of modern JavaScript Ability to write well-structured, semantic, and accessible HTML Confidence writing framework-agnostic, performance-focused JavaScript Awareness of WCAG accessibility guidelines Solid understanding of front-end performance best practices Strong More ❯

someone who has: 2-3+ years of experience working in a web development agency or in-house for a brand Experience developing Shopify themes Strong knowledge of modern JavaScript Ability to write well-structured, semantic, and accessible HTML Confidence writing framework-agnostic, performance-focused JavaScript Awareness of WCAG accessibility guidelines Solid understanding of front-end performance best practices Strong More ❯

base and extremely innovative product suite are in need of an experienced Support Engineer (Software & Infrastructure). This will be a hugely impactful role, working with Ruby on rails & JavaScript SaaS applications, AWS cloud environments and Linux-based systems. The new Senior Software Support Engineer will be part of a senior team and focus on identifying software issues across a … broad range of software products, focusing on fixing bugs and the route cause analysis of these issues. If you have a full stack software engineering background (JavaScript and either current or previous Ruby on Rails) and really see the importance of ensuring a positive user experience through maintaining and improving software applications, this could be the Senior Software Support Engineer … Engineering to prevent repeat issues. Build automation to streamline debugging, triage, and regression prevention. Improve system performance, reliability, and developer experience. What You’ll Bring Strong experience with modern JavaScript frameworks , a good understanding of Ruby on Rails code working with SaaS applications. Skilled with SQL databases at scale and comfortable in Linux environments . Proven ability to diagnose and More ❯

base and extremely innovative product suite are in need of an experienced Support Engineer (Software & Infrastructure). This will be a hugely impactful role, working with Ruby on rails & JavaScript SaaS applications, AWS cloud environments and Linux-based systems. The new Senior Software Support Engineer will be part of a senior team and focus on identifying software issues across a … broad range of software products, focusing on fixing bugs and the route cause analysis of these issues. If you have a full stack software engineering background (JavaScript and either current or previous Ruby on Rails) and really see the importance of ensuring a positive user experience through maintaining and improving software applications, this could be the Senior Software Support Engineer … Engineering to prevent repeat issues. Build automation to streamline debugging, triage, and regression prevention. Improve system performance, reliability, and developer experience. What You’ll Bring Strong experience with modern JavaScript frameworks , a good understanding of Ruby on Rails code working with SaaS applications. Skilled with SQL databases at scale and comfortable in Linux environments . Proven ability to diagnose and More ❯

Investing in your professional development with ongoing quality training and career development opportunitiesThis is the ideal role for a Software Engineer with front-end experience gained with web applications, JavaScript or TypeScript and modern React to advance their career in a meaningful way with our leading, vital charity.As a critical member of our team, you’ll have the chance to … as a Front End Developer, you will need:- Significant experience developing web applications for internal teams and external customers- Proven experience building complex web applications with Next.js- Expertise in JavaScript and/or TypeScript and modern React, including Hooks, Context API, Server and Client Components- The ability to implement best practices in usability, accessibility and inclusive designOther organisations may call … this role Web Developer, JavaScript Developer, Front End Programmer, UI Developer, Web Application Developer, Applications Developer, or App Developer.The closing date for this role is the 9th November 2025. Our commitment to Equality, Diversity & Inclusion: We are happy to consider any reasonable adjustments that candidates may need during the recruitment process and you will be asked whether you require any More ❯

paced project environment. You'll work closely with a cross-functional team to deliver high-quality, scalable web applications using modern technologies. Key skills: Essential: Strong commercial experience with JavaScript , React , and Node.js Proven ability with TypeScript and modern front-end development practices Experience integrating APIs and building performant, responsive interfaces Familiarity with modern tooling and CI/CD pipelines … month initial contract with potential for extension Up to £550 per day, Outside IR35 Hybrid working: 2 days onsite in London If you have strong commercial experience in JavaScript, React, and Node, and are available for your next contract, we'd love to hear from you. More ❯

paced project environment. You’ll work closely with a cross-functional team to deliver high-quality, scalable web applications using modern technologies. Key skills: Essential: Strong commercial experience with JavaScript , React , and Node.js Proven ability with TypeScript and modern front-end development practices Experience integrating APIs and building performant, responsive interfaces Familiarity with modern tooling and CI/CD pipelines … month initial contract with potential for extension Up to £550 per day, Outside IR35 Hybrid working: 2 days onsite in London If you have strong commercial experience in JavaScript, React, and Node, and are available for your next contract, we’d love to hear from you. More ❯

paced project environment. You’ll work closely with a cross-functional team to deliver high-quality, scalable web applications using modern technologies. Key skills: Essential: Strong commercial experience with JavaScript , React , and Node.js Proven ability with TypeScript and modern front-end development practices Experience integrating APIs and building performant, responsive interfaces Familiarity with modern tooling and CI/CD pipelines … month initial contract with potential for extension Up to £550 per day, Outside IR35 Hybrid working: 2 days onsite in London If you have strong commercial experience in JavaScript, React, and Node, and are available for your next contract, we’d love to hear from you. More ❯

paced project environment. You’ll work closely with a cross-functional team to deliver high-quality, scalable web applications using modern technologies. Key skills: Essential: Strong commercial experience with JavaScript , React , and Node.js Proven ability with TypeScript and modern front-end development practices Experience integrating APIs and building performant, responsive interfaces Familiarity with modern tooling and CI/CD pipelines … month initial contract with potential for extension Up to £550 per day, Outside IR35 Hybrid working: 2 days onsite in London If you have strong commercial experience in JavaScript, React, and Node, and are available for your next contract, we’d love to hear from you. More ❯

keep up-to-date with new Salesforce features and best practices. Required Skills: Salesforce Developer with 4+ years of experience, specializing in Cloud and LWC. Skilled in Apex, HTML, JavaScript (ES6+), CSS, SLDS, and Salesforce DX. Experienced in building accessible, WCAG 2.2-compliant portals, integrating via REST/SOAP APIs, and using declarative tools like Flows and Process Builder. Strong … problem-solving and communication skills. Holds key Salesforce certifications including JavaScript Developer I, Platform Developer I & II, and App Builder. All profiles will be reviewed against the required skills and experience. Due to the high number of applications we will only be able to respond to successful applicants in the first instance. We thank you for your interest and the More ❯

paced project environment. You’ll work closely with a cross-functional team to deliver high-quality, scalable web applications using modern technologies. Key skills: Essential: Strong commercial experience with JavaScript , React , and Node.js Proven ability with TypeScript and modern front-end development practices Experience integrating APIs and building performant, responsive interfaces Familiarity with modern tooling and CI/CD pipelines … month initial contract with potential for extension Up to £550 per day, Outside IR35 Hybrid working: 2 days onsite in London If you have strong commercial experience in JavaScript, React, and Node, and are available for your next contract, we’d love to hear from you. More ❯

paced project environment. You'll work closely with a cross-functional team to deliver high-quality, scalable web applications using modern technologies. Key skills: Essential: Strong commercial experience with JavaScript, React, and Node.js Proven ability with TypeScript and modern front-end development practices Experience integrating APIs and building performant, responsive interfaces Familiarity with modern tooling and CI/CD pipelines … month initial contract with potential for extension Up to £550 per day, Outside IR35 Hybrid working: 2 days onsite in London If you have strong commercial experience in JavaScript, React, and Node, and are available for your next contract, we'd love to hear from you. More ❯

Graduate Software Engineer - JavaScript/React/Node | £40–50K | Camden (Hybrid) Join a VC-backed AI SaaS startup that's helping chemical and cosmetics companies launch products globally - solving complex regulatory problems through software. They've raised £3M seed, hit £500K+ in revenue, and are building an all-star team of devs from top UK universities. You’ll work … you: Have a 1st class degree from Imperial, UCL, Cambridge, Oxford, Durham, Bath, etc. Have a passion for building (show us your GitHub or side projects!) Are confident with JavaScript, React, Next.js, Tailwind, Node.js Care about clean code, thoughtful UX, and solving problems end to end Are London-based and up for 3 days/week in our Camden office More ❯