17 of 17 Permanent JavaScript Engineer Jobs in London

Principal JavaScript Engineer (with C++/Java/C# exposure) Location: London (Hybrid – 2 days WFH) Salary: £150,000 - £200,000 (Permanent)pension, private healthcare, gym membership, 25 days + 8 BH holiday allowance, tech/hardware budget. A high-growth software company is building the gold standard in UI frameworks and data-intensive visualisation technology . With … complexity that ordinary web development never touches. What you’ll do Design and optimise a high-performance UI framework used globally in real-time applications. Push the limits of JavaScript, TypeScript, and the browser runtime to handle millions of data points smoothly. Solve deep algorithmic and architectural challenges in rendering, scalability, and memory efficiency. Own features end-to-end … design, code, test, release, and iterate. Contribute to a product used by developers and enterprises worldwide. What you’ll bring Mastery of vanilla JavaScript and TypeScript , with additional exposure to C++, Java, or C# . Strong knowledge of data structures, algorithms, and performance optimisation . Experience with frameworks like React, Angular, or Vue , and a deep understanding of DOM More ❯

Principal JavaScript Engineer (with C++/Java/C# exposure) Location: London (Hybrid – 2 days WFH) Salary: £150,000 - £200,000 (Permanent)pension, private healthcare, gym membership, 25 days + 8 BH holiday allowance, tech/hardware budget. A high-growth software company is building the gold standard in UI frameworks and data-intensive visualisation technology . With … complexity that ordinary web development never touches. What you’ll do Design and optimise a high-performance UI framework used globally in real-time applications. Push the limits of JavaScript, TypeScript, and the browser runtime to handle millions of data points smoothly. Solve deep algorithmic and architectural challenges in rendering, scalability, and memory efficiency. Own features end-to-end … design, code, test, release, and iterate. Contribute to a product used by developers and enterprises worldwide. What you’ll bring Mastery of vanilla JavaScript and TypeScript , with additional exposure to C++, Java, or C# . Strong knowledge of data structures, algorithms, and performance optimisation . Experience with frameworks like React, Angular, or Vue , and a deep understanding of DOM More ❯

Senior Software Engineer/Developer (Full Stack JavaScript) London to £100k Opportunity to progress your career in a senior, hands-on Software Engineer role at a scale-up tech company, that enables smart matching for commercial van drivers and consumers, via job bidding and route optimisation, streamlining processes and delivering CO2 carbon neutral targets, the company has … years, with recent funding of £125 million. You'll be working on complex and interesting systems and can enjoy a range of benefits and perks. As a Senior Software Engineer you'll collaborate as part of an Agile technology team to design and develop, troubleshoot and solve complex software issues to help scale and future proof the business. You … ll work across the full tech stack using JavaScript and Vue.js on the front end, there's a range of other tech in the stack (TypeScript, Node.js, Java, Python and of course a bit of legacy PHP!), you'll be encouraged to explore new technologies and use the best tool for the job as well as own your own More ❯

QA Engineer 🧑💻 | C# | JavaScript | Playwright | FinTech | £95,000💷 My client is seeking a QA Engineer to work across the front, middle and back office. This role is seeking candidates who have exposure to the below skill set and come from a financial background. Location - London📍 Salary - £95,000 💷 Hybrid Working - 3 days per week onsite 🏢 Strong proficiency More ❯

QA Engineer 🧑💻 | C# | JavaScript | Playwright | FinTech | £95,000💷 My client is seeking a QA Engineer to work across the front, middle and back office. This role is seeking candidates who have exposure to the below skill set and come from a financial background. Location - London📍 Salary - £95,000 💷 Hybrid Working - 3 days per week onsite 🏢 Strong proficiency More ❯

Senior Full-Stack Engineer - Go/JavaScript Salary: £80,000 - £90,000 Location: Fully-remote Tech: Go, JavaScript, .NET About the role: We’re working with a leading organisation in the legal sector, renowned for their award-winning approach to technology-driven innovation, in support of their efforts to strengthen their growing SaaS team. They are looking … for a senior software engineer with strong experience in full-stack development using Go & JavaScript. This is a remote role, and it must be noted that all candidates are required to be based in the UK with full eligibility to work without restriction. Responsibilities: Build and enhance scalable SaaS products across the full stack using Go, JavaScript, and … Maintain high engineering standards through structured, well-organised code and effective use of automation. Required experience: Senior-level full-stack development, with expertise in multiple languages & frameworks (namely Go, JavaScript, React, Angular, .NET). API development & integration, microservices, cloud services, and DevOps practices. Agile methodologies with experience in working within a SaaS environment. Cloud-based data technologies and SQL. More ❯

Senior Full-Stack Engineer - Go/JavaScript Salary: £80,000 - £90,000 Location: Fully-remote Tech: Go, JavaScript, .NET About the role: We’re working with a leading organisation in the legal sector, renowned for their award-winning approach to technology-driven innovation, in support of their efforts to strengthen their growing SaaS team. They are looking … for a senior software engineer with strong experience in full-stack development using Go & JavaScript. This is a remote role, and it must be noted that all candidates are required to be based in the UK with full eligibility to work without restriction. Responsibilities: Build and enhance scalable SaaS products across the full stack using Go, JavaScript, and … Maintain high engineering standards through structured, well-organised code and effective use of automation. Required experience: Senior-level full-stack development, with expertise in multiple languages & frameworks (namely Go, JavaScript, React, Angular, .NET). API development & integration, microservices, cloud services, and DevOps practices. Agile methodologies with experience in working within a SaaS environment. Cloud-based data technologies and SQL. More ❯

Senior Full-Stack Engineer - Go/JavaScript Salary: £80,000 - £90,000 Location: Fully-remote Tech: Go, JavaScript, .NET About the role: We’re working with a leading organisation in the legal sector, renowned for their award-winning approach to technology-driven innovation, in support of their efforts to strengthen their growing SaaS team. They are looking … for a senior software engineer with strong experience in full-stack development using Go & JavaScript. This is a remote role, and it must be noted that all candidates are required to be based in the UK with full eligibility to work without restriction. Responsibilities: Build and enhance scalable SaaS products across the full stack using Go, JavaScript, and … Maintain high engineering standards through structured, well-organised code and effective use of automation. Required experience: Senior-level full-stack development, with expertise in multiple languages & frameworks (namely Go, JavaScript, React, Angular, .NET). API development & integration, microservices, cloud services, and DevOps practices. Agile methodologies with experience in working within a SaaS environment. Cloud-based data technologies and SQL. More ❯

Senior Full-Stack Engineer - Go/JavaScript Salary: £80,000 - £90,000 Location: Fully-remote Tech: Go, JavaScript, .NET About the role: We’re working with a leading organisation in the legal sector, renowned for their award-winning approach to technology-driven innovation, in support of their efforts to strengthen their growing SaaS team. They are looking … for a senior software engineer with strong experience in full-stack development using Go & JavaScript. This is a remote role, and it must be noted that all candidates are required to be based in the UK with full eligibility to work without restriction. Responsibilities: Build and enhance scalable SaaS products across the full stack using Go, JavaScript, and … Maintain high engineering standards through structured, well-organised code and effective use of automation. Required experience: Senior-level full-stack development, with expertise in multiple languages & frameworks (namely Go, JavaScript, React, Angular, .NET). API development & integration, microservices, cloud services, and DevOps practices. Agile methodologies with experience in working within a SaaS environment. Cloud-based data technologies and SQL. More ❯

Senior Full-Stack Engineer - Go/JavaScript Salary: £80,000 - £90,000 Location: Fully-remote Tech: Go, JavaScript, .NET About the role: We’re working with a leading organisation in the legal sector, renowned for their award-winning approach to technology-driven innovation, in support of their efforts to strengthen their growing SaaS team. They are looking … for a senior software engineer with strong experience in full-stack development using Go & JavaScript. This is a remote role, and it must be noted that all candidates are required to be based in the UK with full eligibility to work without restriction. Responsibilities: Build and enhance scalable SaaS products across the full stack using Go, JavaScript, and … Maintain high engineering standards through structured, well-organised code and effective use of automation. Required experience: Senior-level full-stack development, with expertise in multiple languages & frameworks (namely Go, JavaScript, React, Angular, .NET). API development & integration, microservices, cloud services, and DevOps practices. Agile methodologies with experience in working within a SaaS environment. Cloud-based data technologies and SQL. More ❯

Senior Software Engineer/Developer (Full Stack JavaScript) London to £100k Opportunity to progress your career in a senior, hands-on Software Engineer role at a scale-up tech company, that enables smart matching for commercial van drivers and consumers, via job bidding and route optimisation, streamlining processes and delivering CO2 carbon neutral targets, the company has More ❯

candidate will contribute to the growth of the platform, exercising an eye for detail across all aspects of the development lifecycle while maintaining organisation and good code hygiene. This engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate will help the Glint platform continue to grow, exercising an eye for detail … across all aspects of the development lifecycle while maintaining organisation and good code hygiene. This Software Engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate values teamwork and collaboration, as well as continuous learning and application of new technologies and trends. With progression in this track, the responsibilities expand to include … and effectively. Understand, respond to, and address customer needs and issues with empathy and timeliness. Required Skills: Proficiency in Python or another typed, object-oriented programming language Proficiency in Javascript and React would be highly beneficial Good knowledge of software methodologies, tools, and typical architectural patterns. Experience with trading and risk management solutions is preferred, but not essential. Experience More ❯

candidate will contribute to the growth of the platform, exercising an eye for detail across all aspects of the development lifecycle while maintaining organisation and good code hygiene. This engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate will help the Glint platform continue to grow, exercising an eye for detail … across all aspects of the development lifecycle while maintaining organisation and good code hygiene. This Software Engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate values teamwork and collaboration, as well as continuous learning and application of new technologies and trends. With progression in this track, the responsibilities expand to include … and effectively. Understand, respond to, and address customer needs and issues with empathy and timeliness. Required Skills: Proficiency in Python or another typed, object-oriented programming language Proficiency in Javascript and React would be highly beneficial Good knowledge of software methodologies, tools, and typical architectural patterns. Experience with trading and risk management solutions is preferred, but not essential. Experience More ❯

candidate will contribute to the growth of the platform, exercising an eye for detail across all aspects of the development lifecycle while maintaining organization and good code hygiene. This engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate will help Glint continue to grow, exercising an eye for detail across all … aspects of the development lifecycle while maintaining organization and good code hygiene. This Senior Engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate values teamwork and collaboration, as well as continuous learning and application of new technologies and trends. With progression in this track, the responsibilities expand to include leading teams More ❯

candidate will contribute to the growth of the platform, exercising an eye for detail across all aspects of the development lifecycle while maintaining organization and good code hygiene. This engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate will help Glint continue to grow, exercising an eye for detail across all … aspects of the development lifecycle while maintaining organization and good code hygiene. This Senior Engineer should be able to effectively communicate both with internal teams and with clients. The successful candidate values teamwork and collaboration, as well as continuous learning and application of new technologies and trends. With progression in this track, the responsibilities expand to include leading teams More ❯

We’re partnering exclusively with one of the most prestigious trading firms in London to find a highly skilled Front-End Software Engineer to join their world-class engineering team. This is an opportunity to work at the very heart of high-performance trading technology — building ultra-responsive, visually intuitive web interfaces for some of the most demanding users … Designing and refining complex front-end architectures for real-time data visualization Working in a culture where engineering excellence and code quality are non-negotiable Tech Stack: Languages: TypeScript, JavaScript (ES6+) Frameworks: React, Redux (or similar) Tooling: Webpack, Babel, Jest, ESLint, Git Bonus: Experience with WebSockets, performance profiling, or custom charting libraries (e.g., D3.js, Highcharts) What They’re Looking … For: Strong experience with React and modern JavaScript/TypeScript Deep understanding of front-end architecture, performance tuning, and scalable component design Experience in fast-paced environments (finance, trading, gaming, or top-tier tech) Passion for clean, maintainable code and UI craftsmanship Why Join? Collaborate with some of the sharpest minds in trading and technology Contribute to software that More ❯

We’re partnering exclusively with one of the most prestigious trading firms in London to find a highly skilled Front-End Software Engineer to join their world-class engineering team. This is an opportunity to work at the very heart of high-performance trading technology — building ultra-responsive, visually intuitive web interfaces for some of the most demanding users … Designing and refining complex front-end architectures for real-time data visualization Working in a culture where engineering excellence and code quality are non-negotiable Tech Stack: Languages: TypeScript, JavaScript (ES6+) Frameworks: React, Redux (or similar) Tooling: Webpack, Babel, Jest, ESLint, Git Bonus: Experience with WebSockets, performance profiling, or custom charting libraries (e.g., D3.js, Highcharts) What They’re Looking … For: Strong experience with React and modern JavaScript/TypeScript Deep understanding of front-end architecture, performance tuning, and scalable component design Experience in fast-paced environments (finance, trading, gaming, or top-tier tech) Passion for clean, maintainable code and UI craftsmanship Why Join? Collaborate with some of the sharpest minds in trading and technology Contribute to software that More ❯