126 to 150 of 177 Permanent JavaScript Engineer Jobs

Principal JavaScript Performance 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 . … 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 Performance 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 . … 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 Performance 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 . … 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 Performance 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 . … 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 ❯

Software Engineer (Java/JavaScript/Node/Full Stack) Gloucester (Hybrid, 2–3 days on site) £42,000 – £62,000 + £7,000 Annual DV Bonus + Excellent Package | Permanent Our client is a digital intelligence consultancy supporting mission-critical programmes in the UK’s National Security sector. Their engineers design and deliver high-assurance software systems … enable government partners to tackle threats such as terrorism, child exploitation, and serious organised crime. The Role You’ll join a collaborative team developing full-stack solutions in Java, JavaScript, or Node.js — building secure platforms and APIs that process and analyse sensitive data at scale. It’s a technically rich environment, combining software engineering, data, and cloud infrastructure in … projects that directly support the UK’s intelligence mission. Key Responsibilities Build and maintain secure, high-performing applications using Java or JavaScript/Node.js. Work on backend services, APIs, and microservice integrations. Contribute to system design and architecture discussions. Support CI/CD and deployment in AWS-based environments. Participate in Agile ceremonies and peer reviews. What You’ll More ❯

Software Engineer (Java/JavaScript/Node/Full Stack) Gloucester (Hybrid, 2–3 days on site) £42,000 – £62,000 + £7,000 Annual DV Bonus + Excellent Package | Permanent Our client is a digital intelligence consultancy supporting mission-critical programmes in the UK’s National Security sector. Their engineers design and deliver high-assurance software systems … enable government partners to tackle threats such as terrorism, child exploitation, and serious organised crime. The Role You’ll join a collaborative team developing full-stack solutions in Java, JavaScript, or Node.js — building secure platforms and APIs that process and analyse sensitive data at scale. It’s a technically rich environment, combining software engineering, data, and cloud infrastructure in … projects that directly support the UK’s intelligence mission. Key Responsibilities Build and maintain secure, high-performing applications using Java or JavaScript/Node.js. Work on backend services, APIs, and microservice integrations. Contribute to system design and architecture discussions. Support CI/CD and deployment in AWS-based environments. Participate in Agile ceremonies and peer reviews. What You’ll 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 ❯

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 ❯

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 ❯

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 ❯

Senior Software Engineer Location: Remote with Sheffield HQ visits 6 times a year Annual Salary: £60,000- £75,000 We are currently looking for Senior Software Engineers that have experience with our Backend tech stack (TypeScript, Node & AWS) Join Our Engineering Evolution at Twinkl At Twinkl, we're not just building software - we're transforming how millions … with React/Next.js + TypeScript for frontend and/or Node.js + TypeScript for backend If you can do both, great! But we do understand that not every engineer has a perfect blend of frontend and backend expertise, and that s okay! If you are experienced in our stack but lean more to one end, but have the … development, particularly in large-scale, cloud-based systems with CI/CD practices. You bring deep expertise in modern frontend frameworks (especially React) and essential web technologies HTML, CSS, JavaScript, TypeScript, and accessibility (a11y). You are experienced with automated testing and familiar with TDD. You ve worked in product-centric teams that prioritise strong engineering principles like TDD More ❯

Senior Engineer Data/Software - London - £90,000 - £130,000 My client are expanding their Data Science & Technology, the team builds the systems and tools that enable trading teams to analyze markets, forecast price movements, and manage risk with speed and precision. If you re passionate about engineering impactful solutions in a high-performance trading environment, this … with local charities 23 days annual leave plus bank holidays Hybrid work model 3 days per week in the London office Collaborate directly with trading and analytics teams to engineer, optimize, and automate front-office workflows and analytical models. Develop robust Python-based services and APIs using modern frameworks, microservice architectures, and best-practice design principles. Design and maintain More ❯

Role: Software Engineer (Java, TypeScript, JavaScript, NodeJS, ReactJS, Python) Location: Remote working with some meetings at offices either in Manchester or London. IR35 status: Outside Length of contract: 5 months initial contract (with a view to possible extension) Overview We are seeking a Software Engineer to support the delivery and maintenance of shared engineering components and templates … Portals (IDPs) serving thousands of users, with a preference for experience in Backstage. Design and implement efficient, reusable GitLab CI pipelines across multiple tech stacks. Develop solutions using TypeScript, JavaScript, NodeJS, ReactJS, Python, and Java. Automate deployments using GitLab CI/CD, Terraform, and EKS. Navigate specific change and governance processes to deliver code and changes to the estate. … Coordinate stakeholders and embed continuous improvement practices across engineering teams. Skills & Experience Strong software development background, especially with TypeScript, JavaScript, NodeJS, ReactJS, Python, and Java. Experience with enterprise-scale engineering environments. Familiarity with DevOps practices and performance measurement. Excellent stakeholder coordination and governance capabilities. If you are interested in the role and would like to apply, please click on More ❯

Senior Software Engineer National Security - SC Clearable - Python - AWS Role: Senior Software Engineer Location: Bristol/Hybrid Work Clearance: SC Cleared/Eligible for SC Salary: £55,000 - £70,000 About the Role We re seeking talented Senior Software Engineers with strong Python and AWS experience to join Agile delivery teams supporting a range of complex … professional development Social: Regular team get-togethers, summer parties, and annual company away-days Onsite Allowances: Expenses provided for lunch and refreshments Apply If you re an ambitious Software Engineer looking to apply your skills to impactful, mission-focused projects, we d love to hear from you. #Python #AWS #React #JavaScript #TypeScript #Kubernetes #Docker #SC #SCCleared #FullStack More ❯

Senior Software Engineer Legacy to Modern C#, .Net SaaS Data A fast-growing SaaS business is investing heavily in its tech platform and building out a senior engineering hub in London. They re on the lookout for a Senior Software Engineer to help drive modernisation, set technical direction, and mentor squads as they scale. You ll design and … exposure to Angular or Telerik libraries Hybrid London role, with 1 2 days a week in the office. Squads value autonomy, collaboration, and building things that last. Senior Software Engineer Legacy to Modern C#, .Net SaaS Data More ❯

Senior Software Engineer (MongoDB/Django) 6-Month Contract Outside IR35 Fully Remote About the Role Aimtech Recruitment are looking for a Senior Software Engineer with deep expertise in MongoDB to help solve complex integration challenges between Django and MongoEngine within a live production environment. This is a hands-on engineering role, suited to someone who can move … MongoDB usage patterns and integration strategies. Help evolve internal tooling, libraries, and data access layers to streamline development. What We re Looking For Proven experience as a Senior Software Engineer with a strong focus on backend systems and database design. Advanced MongoDB knowledge schema design, aggregation pipelines, performance tuning, replication, and indexing strategies. Strong experience with Django and MongoEngine More ❯

Senior Software Engineer (Node.js/TypeScript) They re building a platform that s already making a huge impact and are now looking for a Senior Software Engineer to help shape the next stage of their technology. You ll work across design, product and engineering to build scalable backend systems that are high quality, secure and reliable. Designing, building More ❯

Contract Full-Stack JavaScript Developer &##128205; Location: Remote &##Node.js React.js &##TypeScript AWS &##com ASAP More ❯

Role : Java Software Engineer Salary: Up to 95,000 +10% Bonus Location: London (2 days a week) Key Skills: Java 17+, SpringBoot, React/Typescript, AWS This is a great opportunity for a Senior Java Software Engineer to a travel experiences business. Youll lead backend services and API integrations with a huge number of 3rd partys across their … web and mobile platforms supporting millions of transactions weekly. Responsibilities as the Senior Java Software Engineer: Advocate for best coding practices within the team Uphold development standards and prioritize best coding practices Experience needed as the Senior Java Software Engineer: Backend development experience, working with production level Java based applications Familiarity with cloud services (preferably AWS) A passion … for ensuring best practices and coding excellence are adhered to Experience leading feature development/projects end-to-end If you're a Senior Java Software Engineer who has experience working across mobile applications. More ❯

leading name in defence, aiding Governments, Nations and Societies to defend themselves in an ever-evolving world of cyber crime. We are currently looking for an experienced Senior Software Engineer to join our prestigious Government and Law Enforcement sectors as they continue to see continuous growth and success. A Successful Senior Software Engineer Will Have: Eligibility for SC … oriented programming principles in Java or Python . Knowledge of cloud development on a AWS Experience in hosting and orchestration using Docker , Kubernetes or AWS Autoscaling Groups. Senior Software Engineer Key Details: Discretionary bonus. Hybrid Working. If this role of Senior Software Engineer sounds like a fit for you, make sure to click apply now! If you'd … like to discuss the Senior Software Engineer role further, make sure to get in contact with Zachary Phillips at Anson McCade for a private discussion about the role or any additional details. More ❯

for the most talented Software Engineers to join them. 50-70k (depending on experience) Fully remote Benefits package Key requirements: Over 4 years experience working with Java, React, Javascript, Python Experience using Cloud-based architecture, AWS or Azure DevOps Automated Tools, Jenkins, Docker, OpenShift or Kubernetes Experience using SQL, MongoDB or Elasticsearch Experience using Testing technologies, Cypress, Selenium More ❯

for the most talented Software Engineers to join them. 50-70k (depending on experience) Fully remote Benefits package Key requirements: Over 4 years experience working with Java, React, Javascript, Python Experience using Cloud-based architecture, AWS or Azure DevOps Automated Tools, Jenkins, Docker, OpenShift or Kubernetes Experience using SQL, MongoDB or Elasticsearch Experience using Testing technologies, Cypress, Selenium More ❯

for the most talented Software Engineers to join them. 50-70k (depending on experience) Fully remote Benefits package Key requirements: Over 4 years experience working with Java, React, Javascript, Python Experience using Cloud-based architecture, AWS or Azure DevOps Automated Tools, Jenkins, Docker, OpenShift or Kubernetes Experience using SQL, MongoDB or Elasticsearch Experience using Testing technologies, Cypress, Selenium More ❯