senior javascript developer

Eventogy

<div>STRICTLY NO AGENCIES: We are only accepting direct applications for this role. Any unsolicited CVs sent will be treated as a gift and will not be subject to any terms or fees. 
 
RECRUITERS: DO NOT CALL OR EMAIL US REGARDING THESE ROLES 
We are a highly successful UK based Events Management SaaS company looking for an ambitious Next.js Product Developer to help oversee the next phase of development of our suite of products. As an accomplished Front-End Senior Engineer you will have a solid track record of designing highly scalable technology platforms.
We are gearing up for the next stage of our journey and invite you to discuss how we can collaborate whilst supporting your personal growth.
Role Info:
Current Tech Includes: React.js, Next.js (14+), JavaScript, HTML5, CSS3.
Methodologies: Agile/Kanban, TDD/BDD, Continuous Integration and Delivery, AI-assisted development with Cursor &amp; Claude.
Who we are:
With an existing and highly satisfied customer base of very well-known large international blue chip enterprises, we are a secure and dynamically growing Software business with a 20-year history of stability and profit from offices in Farringdon, London. Our client list includes Deutsche Bank, Santander, BNPP, Ford, Kia, Toyota, Linklaters, Clifford Chance, Freshfields etc. 
Front-End Developer Role:
We are seeking a highly skilled and experienced Next.js Developer to join the front-end team and drive forward the rebuild of our platform. If you are enthusiastic about creating high-quality, user-friendly applications and enjoy working in a collaborative environment, we want to hear from you.
While we have highly skilled developers within our teams, your role will be to provide a more holistic view to our product offering. You will be working with our dev team to design efficient and future-proof interfaces, acting as a key driver for the front-end architecture. You will also be expected to leverage AI-assisted development tooling including Cursor and Claude to accelerate delivery, improve code quality, and embed intelligent development practices across the team. 
 
 
Requirements 
You will:<ul><li>Drive forward the development of the frontend of our platform using React.js and Next.js (14+).</li><li>Convert designs and wireframes into high-quality code.</li><li>Optimise applications for maximum speed, scalability, and responsiveness.</li><li>Ensure consistent implementation of brand and design guidelines across all platforms.</li><li>Develop and maintain reusable code and libraries for future use.</li><li>Conduct thorough testing and debugging to ensure the seamless functioning of applications.</li><li>Collaborate with cross-functional teams, including product managers, developers, and stakeholders, to define and implement innovative solutions for the product direction, visuals, and user experience.</li><li>Drive adoption of AI-assisted development practices, including Cursor and Claude, across the engineering team. 
</li></ul>What are the role requirements?
You will have experience with most of the following:<ul><li>A minimum of 5 years of experience as a React.js/Next.js Developer, preferably working on a SaaS product.</li><li>Proficient understanding of web markup, including HTML5, CSS3, and JavaScript.</li><li>Knowledge of code versioning tools, such as Git.</li><li>Excellent problem-solving skills and a keen eye for detail.</li><li>Strong communication and teamwork skills, with the ability to work effectively with cross-functional teams.</li><li>Proficiency using AI coding tools such as Cursor and Claude to write, review, refactor, and document code efficiently.</li></ul> 
Technical Experience:<ul><li>Languages: JavaScript, HTML5, CSS3.</li><li>Frameworks: React.js, Next.js (14+).</li><li>AI Development Tools: Cursor IDE, Claude (Anthropic), prompt engineering for code generation and review.</li></ul> 
Benefits 
We are extremely ambitious, with bold targets designed to place us among the very best in our industry. As part of our team, you'll have access to multiple career progression routes &mdash; from people and leadership roles to product expertise and project management. The direction you take is yours to choose, and we'll be on hand with the guidance and support you need to succeed.We offer a highly collaborative working environment, excellent support for career progression, and a strong commitment to developing our people &mdash; including investment in AI tooling and training. 
Benefits include:<ul><li>Company pension scheme</li><li>Gym membership</li><li>Hybrid working (3 days a week in our Farringdon, London office)</li><li>Vibrant location with a top-quality coffee shop next door and a bustling food market right outside</li></ul>
We are an equal opportunities employer. You must be eligible to work in the UK, hold a valid visa or UK residency, and be currently based in the UK. You must also be prepared to undergo high-level security clearance. 
Salary: &pound;60,000-&pound;70,000
Location: London
NO AGENCIES &ndash; Please do not attempt to canvas from here.</div>

Senior Front-End Developer (React.js/Next.js)

Capco

<div>Senior Frontend Developer (React) - Edinburgh

Location: Edinburgh (Hybrid) | Practice Area: Technology &amp; Engineering | Type: Permanent

Bring modern web applications to life in the world of financial services

The Role

As a Senior Frontend Developer at Capco, you'll craft clean, responsive, and secure web applications that enhance digital experiences for global financial clients. Working in an agile environment, you'll help shape UI solutions using React and modern JavaScript technologies. You'll play a key role in both hands-on development and guiding best practices across teams.

What You'll Do
<ul>
<li>Build performant and maintainable user interfaces using React (Hooks, Context Suspense) and Typescript</li>
<li>Develop responsive cross-browser compatible layouts using modern CSS (Flexbox, Grid), CSS-in-JS or modular CSS, and component libraries such as MUI or Tailwind</li>
<li>Optimise application performance using techniques like code-splitting, memorization, and lazy loading.</li>
<li>Ensure secure application development following OAuth2, OpenID Connect, and JWT principles</li>
<li>Collaborate closely with backend, design, and product teams to shape engaging user journeys</li>
<li>Contribute to team learning through code reviews, mentoring, and sharing best practices</li>
</ul>
What We're Looking For
<ul>
<li>Strong proficiency in JavaScript (ES5/ES6+) and Typescript</li>
<li>Hands-on experience building production application in React 18+</li>
<li>Solid understanding of state management (Context API, Redux Toolkit, or similar)</li>
<li>Experience consuming RESTful APIs and handling async data with modern patterns</li>
<li>Strong CSS skills including Flexbox, Grid, and CSS pre-processors like SASS/LESS</li>
<li>Familiarity with modern build and tooling ecosystems such as Vite, Webpack or similar</li>
<li>Experience with frontend testing using Jest, React Testing Library, Cypress or Playwright</li>
<li>A passion for UI performance, quality, and delivering clean code</li>
</ul>
Bonus Points For
<ul>
<li>Exposure to Vue, Angular, or Next.js in production environments</li>
<li>Understanding of secure application design and frontend performance optimisation</li>
<li>Experience deploying applications in CI/CD pipelines</li>
<li>Working knowledge of design systems, component-driven development and tools like Storybook</li>
<li>Strong debugging skills and ability to work in fast-paced agile teams</li>
<li>Curiosity for new technologies and experimentation</li>
</ul>
Why Join Capco
<ul>
<li>Deliver high-impact technology solutions for Tier 1 financial institutions</li>
<li>Work in a collaborative, flat, and entrepreneurial consulting culture</li>
<li>Access continuous learning, training, and industry certifications</li>
<li>Be part of a team shaping the future of digital financial services</li>
<li>Help shape the future of digital transformation across FS &amp; Energy.</li>
</ul>
Benefits

We offer a competitive, people-first benefits package designed to support every aspect of your life:
<ul>
<li>Core Benefits: Discretionary bonus, competitive pension, health insurance, life insurance and critical illness cover.</li>
<li>Mental Health: Easy access to CareFirst, Unmind, Aviva consultations, and in-house first aiders.</li>
<li>Family-Friendly: Maternity, adoption, shared parental leave, plus paid leave for sickness, pregnancy loss, fertility treatment, menopause, and bereavement.</li>
<li>Family Care: 8 complimentary backup care sessions for emergency childcare or elder care.</li>
<li>Holiday Flexibility: 5 weeks of annual leave with the option to buy or sell holiday days based on your needs.</li>
<li>Continuous Learning: Your growth, your way - minimum 40 hours of training annually. Take your pick; workshops, certifications, e-learning. Also, Business Coach assigned from Day One: Get one-on-one guidance to fast-track your goals and accelerate your development.</li>
<li>Healthcare Access: Convenient online GP services.</li>
<li>Extra Perks: Gympass(Wellhub), travel insurance, Tastecard, season ticket loans, Cycle to Work, and dental insurance.</li>
</ul>
Inclusion at Capco We're committed to making our recruitment process accessible and straightforward for everyone. If you need any adjustments at any stage, just let us know &ndash; we'll be happy to help. We value each person's unique perspective and contribution. At Capco, we believe that being yourself is your greatest strength. Our #BeYourselfAtWork culture encourages individuality and collaboration &ndash; a mindset that shapes how we work with clients and each other every day.

#LI-DNI</div>

Senior Frontend Developer - React

DATATRONiQ

<div>
 
 🚀 DATATRONiQ stands out as a pioneering deep-tech 💪 startup for the industrial IoT in Germany. Our platform offers a one-stop solution for companies to monitor and optimize their assets and processes. Our device management and data acquisition technology generate high-quality data for our AI models deployed on edge. We believe in an open and collaborative environment to foster the best ideas from the most creative people, and we want to talk to you!
 
 
 
 As a (senior) fullstack developer at DATATRONiQ, you will have the opportunity to work on a cutting-edge IoT platform that utilizes AI to analyze data from industrial processes. Our platform uses machine learning algorithms to detect anomalies and identify patterns that may indicate potential issues with equipment and continuously monitors the quality of parts. Our platform also provides IIoT device management and software connectors for data acquisition from a very broad range of manufacturing machines and control systems.
 
 
 
 We are looking for multiple skilled Typescript (Javascript) fullstack developers (or those who want to become one) to join our team. You will be responsible for developing and maintaining the dashboard stack (React, Koa/Express), which is run on Kubernetes and communicates with a handful of microservices written in Golang and Scala. You should have experience working with Typescript (or Javascript), as well as a strong understanding of fullstack development; ideally you have a good eye for design/UI/UX and are also interested in working with AI and machine learning technologies, as well as data analysis and visualization in general.
 
 
 
 At DATATRONiQ, you will be a key member of our engineering team and start contributing from day one. We continuously improve our development processes and take pride in our commitment to delivering high-quality products. To do so, we make a real effort to rank at the top of the Joel Test for engineering teams. We aim to create a healthy and productive engineering environment and encourage collaboration between remote and on-site team members. We do regular pair-programming sessions, and on Fridays we meet (online and offline) to finish the week with a mix of hackathons and show and tell.
 
 
 Tasks
 
 <ul>
 
 <li>
 Work in an agile environment to ship frontend and backend components; be curious about new tech
 </li>
 
 <li>
 Implement new features using Typescript and Javascript (Node.js &amp; Express in the backend, React &amp; Storybook in the frontend) and keep the overall stack up-to-date
 </li>
 
 <li>
 Advocate for high-quality code and appreciate good tests/coverage; occasionally write or improve tooling to further automate manual steps
 </li>
 
 <li>
 Actively contribute to decision-making processes how we build new features and participate in shaping the product roadmap
 </li>
 
 </ul>
 
 Requirements
 
 <ul>
 
 <li>
 Completed studies in the field of computer science, mathematics, physics or similar
 </li>
 
 <li>
 Good programming skills and solid knowledge of agile software development
 </li>
 
 <li>
 Expertise in working with databases
 </li>
 
 <li>
 Openness for new technologies
 </li>
 
 <li>
 Great written and spoken English; German is a plus
 </li>
 
 <li>
 A high level of commitment, initiative and enthusiasm for IT
 </li>
 
 <li>
 A bonus, but not mandatory: familiarity with technologies such as React, Storybook, Node.js, Docker/Kubernetes, e2e testing, and Linux
 </li>
 
 </ul>
 
 Benefits
 
 <ul>
 
 <li>
 Participation in a young company in a future-oriented industry
 </li>
 
 <li>
 Implementation of artificial intelligence in the context of industrial IoT
 </li>
 
 <li>
 Attractive workplace with innovative technology and modern equipment; hybrid work is also possible
 </li>
 
 <li>
 Exciting challenges and recognition for top performances
 </li>
 
 <li>
 A company culture where honesty, professionalism, and integrity run deep
 </li>
 
 <li>
 Flat hierarchies, quick decision-making processes, and an agile company structure
 </li>
 
 <li>
 Budget for personal and professional development as well as for equipment of your choice
 </li>
 
 <li>
 Snacks, beverages, subscription for Spotify, public transport ticket
 </li>
 
 <li>
 Competitive salary commensurate with experience and market standards
 </li>
 
 </ul>
 
 
 Did we spark your interest?
 
 
 
 This is a unique and exciting opportunity to work on a product that has the potential to make a significant impact in the industrial manufacturing sector. DATATRONiQ platform is built with TypeScript, Golang, Python, Scala, C++ and deployed as microservices on various Cloud environments and on-prem virtual machines using Kubernetes.
 
 
 If you are passionate about using your skills to solve challenging problems and make a difference, we really would like to talk to you. We are looking forward to your application!
 
 
 
 
 We ask recruitment agencies and headhunters to refrain from contacting us.
 
 
</div>

(Senior) Developer Fullstack (Typescript / Javascript / Node.js)

YO IT Consulting

<div>
 
 Job Title:
 
 Software Engineering
 
 
 
 Job Type:
 
 Contractor (10-12 hours per week)
 
 
 
 Location:
 
 Remote
 
 
 
 Job Summary
 
 
 
 We are looking for experienced software engineers to help train and evaluate next-generation AI systems through real-world software engineering tasks. This role is best suited for developers who can reason through unfamiliar codebases, explain engineering decisions clearly, and solve practical backend, full-stack, systems, or infrastructure-related problems.
 
 
 No prior AI experience is required. What matters most is strong software engineering judgment, clean technical communication, and the ability to evaluate code, architecture, tradeoffs, and implementation quality.
 
 
 
 Key Responsibilities
 
 
 
 <ul>
 <li>
 Work on challenging software engineering tasks across backend, full-stack, infrastructure, and systems-related projects.
 </li>
 <li>
 Review, debug, improve, and explain code across different technical environments.
 </li>
 <li>
 Design or evaluate practical solutions involving APIs, databases, services, integrations, testing, and deployment workflows.
 </li>
 <li>
 Identify tradeoffs around scalability, maintainability, performance, reliability, security, and developer experience.
 </li>
 <li>
 Communicate technical reasoning clearly in writing, including why a solution works and what alternatives were considered.
 </li>
 <li>
 Collaborate with the customer&rsquo;s team on technical reviews, implementation decisions, and problem-solving exercises.
 </li>
 <li>
 Adapt quickly to new codebases, frameworks, and technical requirements.
 
 
 </li>
 </ul>
 
 Required Skills And Qualifications
 
 
 
 <ul>
 <li>
 5+ years of hands-on software engineering experience.
 </li>
 <li>
 Strong experience in at least one backend or full-stack engineering environment, such as Python, JavaScript/TypeScript, Node.js, Java, C#, .NET, C++, Go, Ruby, PHP, or similar.
 </li>
 <li>
 Experience building, maintaining, or reviewing production-level applications, APIs, services, databases, or integrations.
 </li>
 <li>
 Strong understanding of software engineering fundamentals, including debugging, testing, code quality, architecture, and technical tradeoffs.
 </li>
 <li>
 Ability to explain complex engineering decisions clearly and objectively.
 </li>
 <li>
 Comfortable reading and reasoning through unfamiliar code or technical requirements
 
 
 </li>
 </ul>
 
 Preferred Qualifications
 
 
 
 <ul>
 <li>
 Experience with cloud environments such as AWS, GCP, or Azure.
 </li>
 <li>
 Experience with CI/CD pipelines, DevOps workflows, containers, monitoring, or production operations.
 </li>
 <li>
 Experience with frontend frameworks such as React, Next.js, Angular, Vue, or React Native.
 </li>
 <li>
 Open-source contributions, public GitHub work, technical writing, or strong examples of past engineering work.
 </li>
 <li>
 Experience mentoring engineers, reviewing code, or making architecture decisions.
 </li>
 </ul>
</div>

JavaScript/TypeScript Developer - Remote

The Service Directory

Join our engineering team in Glasgow to help modernise and scale our platform used by thousands of clients across the UK.The Service Directory is an online purchasing system primarily used by care homes and nurseries within the UK. We sit between the customer and supplier to help make efficiencies in accounting, reporting, and in controlling spend.We're looking for a full-stack mid-level software engineer to join us at our office in Glasgow. You'll play a key role in building new features, fixing issues, and occasionally helping to rewrite our legacy PHP system into a modern ReactJS + Express architecture. The role is best suited for someone who describes themselves as a web developer with a passion for software engineering, has exceptional problem-solving skills, and is comfortable owning features from design to deployment while working closely with other developers.What you bring:<ul><li>Experience with JavaScript, TypeScript and Node.js</li><li>Some experience using ReactJS that interacts with another back-end routing framework (Express or similar).</li><li>Experience with designing and using a Rest API.</li><li>3+ years professional software engineering experience or BSc degree in Computing Science (or similar).</li><li>Understand web security concepts and be able to consistently write secure code.</li><li>Ability to read, understand, and make changes to existing code to make improvements to performance and add new features.</li><li>Experience working with relational databases (MySQL or PostgreSQL).</li></ul>Nice to have:<ul><li>Familiar with PHP.</li><li>Experience with maintaining a large codebase.</li><li>Knowledge of Linux command line.</li></ul>Work setup:<ul><li>Hybrid working with Monday&ndash;Thursday in the office, and work from home on Fridays.</li><li>15 additional 'work from home' days to use throughout the year.</li></ul>Benefits:<ul><li>29 days annual leave, plus your birthday off.</li><li>Hybrid work schedule (see above).</li><li>Collaborative, friendly team culture with opportunities for growth and mentorship.</li><li>Modern tech stack and a chance to influence major technical decisions.</li></ul>Pay: From &pound;36,000.00 per yearEducation:<ul><li>Diploma of Higher Education (preferred)</li></ul>Experience:<ul><li>Node.js: 2 years (required)</li></ul>Work authorisation:<ul><li>United Kingdom (required)</li></ul>Work Location: In person

Mid-level Node.js Software Engineer

Betfred

<div><h2 class="jobSectionHeader">About Us</h2>
Our mission is to dominate the betting and gaming industry on a global scale and we need the very best Tech talent to help us achieve this.
We recently migrated all of our customers onto our very own proprietary platform - so it's an exciting time to join us. With the help of our new platform, we're able to pioneer new products and drive more advanced, creative technologies. The result? Unrivalled experiences for millions of customers worldwide.
Betfred's Technology department is driven by innovation, and you'll be at the heart of unlocking our new platform's potential. So, if you want to help shape the future of betting and gaming, then it's to time to join us. 

<h2 class="jobSectionHeader">Job Purpose</h2>
We are setting up a new team to support our platform and we want a Senior Frontend Developer to join the new team early on in the process to work and take an active role in designing the implementation of a new greenfield web app frontend for the platform.
We are looking for a highly skilled frontend engineer with proven experience creating complex rich internet applications using the ReactJS framework. You will have a well-structured approach and will recognise the benefit of good system architecture and design in order to deliver the high standards we want. 

<h2 class="jobSectionHeader">Job Duties</h2>
Write clean, maintainable and scalable code that meets the requirements of the project
Debug and resolve software issues, including fixing bugs and optimizing performance
Collaborate with cross-functional teams, including Designers, Testers, Project Managers and Product Owners, to deliver high-quality software
Participate in code reviews and provide constructive feedback to peers
Implement and follow software development processes, including Agile and Scrum methodologies
Stay up-to-date with new technologies and methods, applying this knowledge to improve software development processes
Document software design, code and test procedures
Participate in the estimation of software development projects
Participate in customer and end-user interactions to gather requirements and provide support
Contribute to the development and maintenance of technical documentation, including user manuals and help systems
Mentor Junior Developers and assist with their professional development 

<h2 class="jobSectionHeader">Knowledge, Skills and Experience</h2>
Significant commercial experience in the web stack; HTML, CSS and JavaScript
Have proven experience in a similar role on a similar scale system
Expert knowledge of ES2015
Proven experience with ReactJS
Experience writing middlewares in Node.js
Use of build tools, particularly Webpack
Unit and functional testing is a big bonus
Source Control using Git
CSS pre-processing with Sass
Significant plus if you&rsquo;ve got any .NET experience
Experience working in an Agile environment
Excellent knowledge of software and application design and architecture
Experience in the gaming industry is a significant advantage
An excellent communicator, both verbal and written
Hard working and willing to go above and beyond learning new skills
Love working as part of a team and collaborating with others
An interest in troubleshooting and problem solving 

<h2 class="jobSectionHeader">What is in it for me?</h2>
We offer a variety of competitive benefits, some of which vary depending on the role you&rsquo;re recruited to. Some of what you can expect in this role includes:
A competitive rate of pay and pension contribution ( &pound;50,000-&pound;65,000)
Generous discretionary bonus schemes, incentives and competitions
An annual leave entitlement that increases with length of service
Access to an online GP 24/7, 365 days a year for you and your immediate family.
Employee wellbeing support through our Employee Assistance Programme
Enhanced Maternity &amp; Paternity Pay
Long Service Recognition
Access to a pay day savings scheme, financial coach and up to 40% of your earned wage ahead of payday, through Wagestream.
For More information, visit our https://betfredcareers.com/why-join/</div>

Senior Front End Developer

Search 8069+ Senior javascript developer jobs near you this July. New roles added regularly across leading industries. Apply today.

8069 senior javascript developer jobs Near Me

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