39 Javascript jobs in London

About Eventogy:

NO AGENCIES - Please do not attempt to canvas from here

Eventogy is a leading event management platform that caters to large corporate enterprise businesses, such as banks, law firms, and government bodies. We specialise in providing event management solutions for highly regulated industries, with a strong focus on security and compliance. As a design-first organisation, we are currently undertaking a complete rebuild of our platform to create an even more intuitive and engaging user experience.

We are seeking a skilled Javascript Developer to join our team and play a crucial role in implementing our redesigned platform. The successful candidate will work closely with our design and development teams to create pixel perfect and highly functional web applications, ensuring an exceptional user experience.

Responsibilities:

1. Collaborate with UX/UI designers and back-end developers to create visually appealing, user-friendly, and highly functional and responsive web applications.
2. Convert designs and wireframes into high-quality HTML, CSS, and JavaScript code.
3. Optimize applications for maximum speed, scalability, and responsiveness.
4. Ensure consistent implementation of brand and design guidelines across all platforms.
5. Develop and maintain reusable code and libraries for future use.
6. Stay up-to-date with the latest front end development technologies and best practices.
7. Conduct thorough testing and debugging to ensure the seamless functioning of applications.
8. 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.

Requirements

1. A Bachelor's degree in Computer Science, Web Development, or a related field.
2. A minimum of 3 years of experience as a Front End Developer, preferably in the event management or technology sector.
3. Proficient understanding of web markup, including HTML5, CSS3, and JavaScript.
4. Experience building NextJS Web Applications using Typescript.
5. Familiarity with TailwindCSS.
6. Experience with responsive and adaptive design, as well as an understanding of the technical limitations and constraints of web applications.
7. Strong understanding of cross-browser compatibility issues and ways to work around them.
8. Knowledge of code versioning tools, such as Git.
9. Excellent problem-solving skills and a keen eye for detail.
10. Strong communication and teamwork skills, with the ability to work effectively with cross-functional teams.

Benefits

All applicants MUST have working Visas or be UK residents and be currently present in the UK.

This is a hybrid role and we can negotiate the terms of your office presence, but for your information, we currently come in 2-3 times a week to the Farringdon office in London.

We have the finest coffee shop on our doorstep. A food market right in front of the office. Access to gym membership, with conditions! Training is catered for as and when needed. Pret coffee subscription included

NO AGENCIES - Please do not attempt to canvas from here.

Salary: from £50,000 subject to qualification.

JOB SUMMARY

We are looking for a highly motivated Senior Vue.js Developer to join our team.  You will be responsible for evolving and scaling our existing platforms as well as working on new greenfield projects. Mentoring other developers, practising excellent communication and motivation within the team is essential. There is a lot of scope for responsibility and the individual should be comfortable taking ownership of and managing all aspects of the front-end stack. You will join a team of front-end, back-end and database developers to deliver modern Progressive-Web-Applications, Applications and Websites.

ESSENTIAL DUTIES

• Evolving and scaling our existing platforms with informed technical decisions.
• Conceptualizing and developing new, stimulating user-facing features.
• Creating reusable libraries and efficient code for broader team use in future projects.
• Prioritizing the optimization of applications for optimal speed and scalability.
• Managing Pull Requests in alignment with the team's workflow, ensuring project expectations and deadlines are met.
• Refining internal processes to enhance the performance, reliability, and usability of our platforms.
• Identifying and making improvements to any performance-related issues affecting our web and mobile-based applications.
• Upholding stringent security standards for web and mobile applications, promptly resolving and protecting against vulnerabilities.
• Staying in tune with innovations and advancements in JavaScript and applying them to keep our applications highly competitive and adept.
• Mentoring team members in a supportive environment to further their growth and understanding of JavaScript's core concepts and best practices.
• Fostering an atmosphere for innovation and positivity, inspiring team members to deliver their best work consistently.

Requirements

Essential Skills

• Strong understanding of the following technologies:
• ES6 & JavaScript
• Vue.js
• Web markup, including HTML & CSS
• Asynchronous request handling using the likes of REST or GraphQL
• Front-end build tools, such as Vite, Webpack and CLIs
• Git and its related platforms like Github or Gitlabs
• Package management using npm
• Browser rendering behaviour and performance
• Passion for writing quality, high-performance and maintainable code following best practices

Desirable Skills

• Typescript
• Nuxt.js
• Node.js
• Storybook
• CI/CD, Pipeline management, GitHub Actions
• Docker
• Prototyping/Storyboarding
• Graphics editing with the likes of Figma, Photoshop & Illustrator
• Mobile & Responsive design
• Testing tools like Vitest, Jest, Playwright, Cypress

 KEY DELIVERABLES

• Leverage advanced JavaScript techniques to develop high-quality, efficient code, assess coding opportunities, conduct robust code reviews, streamlining codebase, and prototypes to continuously improve performance and user experience. Accurately estimate the timescales for design, development and testing phases to ensure realistic and effective project scheduling.
• Evaluate the potential impact of each change request, proactively communicating any associated risks to project managers and the leadership team.
• Collaborate proactively with the development team to coordinate the seamless delivery of high-quality application code.

• REQUIRED EXPERIENCE / QUALIFICATIONS
• IT professional with 5 years of design and technical background and knowledge
• Proven experience in web design and development
• Analytical and problem-solving skills
• Self-motivated and able to work/travel independently
• Proactive, able to work with a high level of responsibility and autonomy, able to work under pressure
• Flexible in terms of working time with a priority on “getting the job done”
• A good team player who can perform and work on a wide variety of tasks simultaneously

COMPETENCIES/SKILLS

Technical Skills

• Advanced JavaScript expertise
• Empowered decision making
• Strong oral and written communication skills
• Cultivates teamwork and collaboration
• Effective allocation and management of resources

Personal Effectiveness

• Acts with integrity and professionalism
• Demonstrates adaptability and resilience
• Excellent organizational and time management skills
• Sensitivity towards cultural diversity
• Takes a proactive lead, handles queries, manages issue resolution
• Commitment to quality, detail-oriented approach, and a strong work ethic

Interpersonal Skills

• Influences others across all levels
• Foster open communication
• Builds and maintains positive relationships
• Delivers persuasive presentations to senior management

Growth & Innovation

• Challenges existing procedures
• Identifies weaknesses and proposes improvements
• Encourages continuous learning and improvement

The above statements are intended to describe the general nature and level of work being performed by people assigned to this job. They are not intended to be an exhaustive list of all responsibilities, duties, and requirements.

Location: Offices in London (City) & Hampshire (Fleet)
The full job description covers all associated skills, previous experience, and any qualifications that applicants are expected to have.
About Us

Alphix is a privately held, forward-thinking business part of Fundamental Group, an award-winning, global leader in the B2B and financial marketing services sector. As a fast-paced scale-up, Alphix is experiencing rapid growth, securing an increasing number of clients and delivering cutting-edge, privacy-first marketing technologies. Our solutions empower B2B marketers to become more agile and responsive through the power of AI and data.
This is a highly innovative environment that thrives on change. We seek individuals who embrace transformation, dislike stagnation, and have a deep sense of autonomy and accountability. At Alphix, your contributions directly shape the future of B2B marketing.

The Role

We are seeking an experienced Senior JavaScript full stack developer who loves modern web design and backend development, has a great eye for detail and is excellent problem solver. Naturally you will be able to produce great UI/UX in conjunction with our designers and be able to take on complex backend development using NodeJS and your database skills. You will be self-motivated and able to take on project briefs and lead technical projects regularly as well as assisting other engineers openly.
Key Responsibilities:

• Own Project Delivery: Take ownership of development projects, delivering high-quality work within agreed timelines and scope. Communicate risks early and keep the product team informed to ensure smooth and transparent collaboration.
• Drive Cross-Functional Collaboration: Work closely with stakeholders and product managers, designers, to translate business needs into actionable technical solutions.
• Support Estimation and Risk Management: Collaborate with the product team to provide realistic estimates, identify potential technical risks early, and play an active role in finding solutions to keep projects on track.
• Build with Security, Speed, and Scale in Mind: Make sure the features we build are safe, run fast, and can handle growth, by following best practices and staying mindful of how our choices today affect performance and scalability tomorrow.
• Write and Review Quality Code: Deliver secure, high-quality code, and help maintain high standards by reviewing, debugging, and improving code written by others.
• Maintain High-Quality Engineering Documentation: Create, organize, and continuously update technical documentation to ensure clarity, knowledge sharing, and long-term maintainability of systems and features.
  

Qualifications & Experience:

• Proven track record as a Senior Software Engineer in a SaaS environment.
• Deep technical expertise in:
• Databases such as MySQL, Singlestore, and BigQuery.
• Expertise working with third party data feed APIs.
• Strong understanding of software engineering best practices, feature deployment processes and testing.
• Ability to drive rapid decision-making, manage competing priorities, and deliver under pressure.
• Strategic thinking combined with a hands-on ability to execute technical solutions.
• Strong problem-solving and communication skills in a collaborative, fast-paced environment.
• Experience developing and maintaining clear, well-structured engineering documentation.
• Experience in high-growth startup or scale-up businesses is highly desirable.
• Passion for continuous learning, improvement, and operational excellence.
• Proactive, self-motivated, and eager to take on technical ownership.
• Experience working with remote or hybrid teams.
  

What we offer:

• Supportive, friendly colleagues who work together to achieve shared goals.
• Competitive salary and a discretionary bonus.
• Career growth opportunities: Were committed to your success and offer recognition, rewards, and the training and support needed for advancement.
• A dynamic and innovative work environment within a contemporary, team-focused, and forward-thinking company.
• 100% Club: A prestigious, peer-nominated award where top performers earn an all-expenses-paid vacation (previous destinations include Dubai, skiing in France, diving in the Red Sea, and Mykonos).
• Excellent benefits including pension contribution, private healthcare, life cover, cycle scheme, season ticket loans, 25 days annual leave pro rata, 2 days paid leave for charity work, study loans and free snacks in the office.
  

If youre looking for a company that values your contributions, invests in your development, and offers exciting rewards, Fundamental Media is the place for you!

We are an equal opportunities employer and welcome applications from all suitably qualified persons regardless of their race, sex, disability, religion/beliefs, sexual orientation, or age.
Personal data collected will be used for recruitment purposes only. Strictly no agencies.

We are looking for a passionate and skilled Software Developer to join our growing development team. You will be responsible for designing, developing, and maintaining high-quality software applications, ensuring optimal performance, reliability, and scalability. As a part of the development team, you will collaborate with cross-functional teams to create software solutions that meet business needs.

• Software Development : Write clean, efficient, and well-documented code for new features, updates, and bug fixes.
• System Design : Participate in the design and architecture of software applications and systems.
• Collaboration : Work closely with product managers, UX/UI designers, and QA engineers to deliver high-quality software.
• Testing : Write and maintain unit tests, perform debugging and troubleshooting to ensure software stability and performance.
• Version Control : Use version control tools like Git to manage codebase and collaborate with other developers.
• Continuous Improvement : Stay up-to-date with new technologies, programming languages, and best practices to constantly improve development processes.
• Code Reviews : Perform peer reviews of code to ensure best practices and maintain code quality standards.
• Documentation : Document the software development process, code changes, and other technical processes for future reference.

Software Developer – Contract – Fully Remote

VIQU have partnered with a leading public sector organisation to recruit a .NET / C# Software Developer for a short-term contract.

The Role:

This Software Developer role will see the successful developer support the ongoing development, customisation, and maintenance of internal web applications and solutions.

You will work on .NET web development, alongside Microsoft Power Apps. Your work will focus on pro-code development of web applications, as well as customisations for Power Apps.

Key Skills & Experience:

• Solid commercial experience as a Software Developer, developing web applications using .NET and C#
• Proficiency building and customising Model-Driven Apps and Canvas Apps (Power Apps experience).
• Strong working knowledge of SQL and Microsoft Dataverse
• Experience developing and consuming REST APIs, including the Dataverse Web API and Microsoft Graph API
• Proven experience writing Windows scripts (e.g. PowerShell, batch scripting)
• Agile (SCRUM)
• Azure DevOps
• Strong communication skills and a collaborative mindset

Contract Overview

• Role: Software Developer
• Length: 5-month contract
• IR35: Inside IR35
• Rate: £330 per day
• Location: Fully Remote  

Apply now to speak with VIQU IT in confidence. Or reach out to Suzie Stone via the VIQU IT website.

Do you know someone great? We’ll thank you with up to £1,000 if your referral is successful (terms apply).

For more exciting roles and opportunities like this, please follow us on LinkedIn @VIQU IT Recruitment.

LMAX is renowned for its high-performance, ultra-low latency (we measure in microseconds) exchange written in core Java. We constantly push technology further than most, especially in our greenfield projects, driving the financial industry in new directions.

Developers are encouraged to constantly develop and learn new skills. Pair programming supports continual growth of knowledge and sharing of expertise, alongside regular team rotations ensuring everyone gains first-hand knowledge on all areas of our codebase. Friday afternoons are set aside as personal development time where you can explore a different coding language, research bleeding edge technologies, or play around with one of our environments. There is also regularly scheduled time to improve developer experience and reduce technical debt – directed by developers.

Our continuous integration and testing culture allows us to have confidence in our builds and develop quickly. We have over 30,000 acceptance tests running every 25 mins in our CI, alongside extensive test suites (performance, compatibility, migration, resilience). Continuous Delivery was pioneered at LMAX one of the authors worked here while writing the book). Due to pair programming and testing we don’t do pull requests, we push directly to our monorepo with a “revert first, ask questions later” attitude.

If you want to work with great developer practices like fast feedback across all aspects of your work, a cooperative culture, and only shipping things when they’re ready, while being at the heart of a thriving exchange with opportunities to learn about the finance industry, then LMAX is for you!

What you should expect:

•Collaborative office environment with constant pairing and plenty of social activities

•Work across the stack to solve a problem – You might be working with a performance critical component, integrating a new blockchain, or designing a greenfield cloud based system

•Regular opportunities to learn and develop yourself with internal tech talks, ability to travel to conferences, and dedicated time for your personal development

What you’ll be working with:

•Backend: Distributed, event-driven core Java (90% of the code-base), MySQL, Kafka

•Frontend: Javascript, Vue.js

•Deployment: Kubernetes, Nomad

•Data analytics: Python & Jupyter notebooks, Parquet, Docker

•Testing: JUnit, JMH, JCStress, Jenkins, Selenium, many in-house tools.

•OS: Linux (Fedora for development, Rocky in production)

The LMAX way is to use the right tool for the job so this is just a flavour of what you’ll be working with, and isn’t a list of requirements!

Requirements

•Be passionate about software development. Bad code offends you!

Mustard Systems is a team of 65 people dedicated to developing market leading sports models and trading strategies. Applications of our research are widespread across multiple sectors including betting, insurance, finance and the media, as well as giving advice to coaches and owners of sporting teams. Our aim is to predict sport as accurately as possible, and we achieve this by combining large, rapidly changing datasets with home grown software and statistical models.

We enjoy a fast-paced, ever-changing environment, offering fresh challenges which are both rewarding and enjoyable. Our ambitions are high, aiming to create best-in-class systems in a highly competitive field. In the coming year, we will be working on expanding our trading strategies and data feeds. 

What You’ll Work On:

• Develop and support new and existing trading strategies
• Design and implement new features for trader UIs with focus on UX
• Integrate with new liquidity providers and optimize existing connections
• Collaborate closely with quants, traders, and other engineers on trading strategies and analytics
• Gather data to improve predictive capabilities, including improving the queryability and quality of existing data.
• Enhance system visibility for our teams to make informed decisions

We work with an agile approach, following a flexible plan that adapts to new information and opportunities as they arise. Developers are a core part of this process, taking full ownership of their software throughout its lifecycle—from design and development to testing, review, and production support.

At Mustard, we value quick delivery and real-world impact over perfect code. If you’re an engineer who thrives on solving problems quickly and enjoys a flexible, outcome-focused culture, you’ll fit right in.

Key Responsibilities

• Design and Build Impactful Features: Develop new features that align with and drive our business goals, delivering high-quality code that brings measurable value.
• Collaborate on Code Quality: Review and test code from teammates to ensure functionality, maintainability, performance, and quality standards.
• Support in Production: Take ownership of your team’s software in production, ensuring stability and quickly addressing any issues that arise.
• Cross-Team Collaboration: Work closely with other development teams on cross-functional projects, and partner with traders and quants to design and implement the best solutions to real business problems.
• Participate in Out of Hours Support for our Software Systems.

Core Tech Stack:

• Languages: Python (Python 3.10+), JavaScript/TypeScript for frontend work, and Go for select infrastructure
• Tools: RabbitMQ and Kafka for messaging, PostgreSQL for data storage, Websockets for frontend communication
• Environment: Linux servers
• Observability: Prometheus, Grafana and Zabbix

Requirements

Must-Haves:

• Strong background in software development, with strong experience with Python.
• A degree in Computer Science or a numerical subject from a top university.
• Exceptional communication skills, enabling you to convey complex technical ideas clearly to both technical and non-technical audiences.
• Strong decision-making abilities, with a knack for making thoughtful trade-offs in both implementation and architectural choices, balancing innovation and practicality.

Nice-to-Haves:

• Familiarity with building event-driven systems
• Comfort with Linux/Unix environments
• Experience working with JavaScript and/or TypeScript
• Knowledge of relational databases, including both querying and schema design.
• Cloud experience, including design and deployment

Benefits

Why join Mustard Systems?

• Work on cutting-edge systems in a competitive and innovative field.
• Collaborate with a smart, driven team, where your contributions directly impact business performance.
• Opportunity to drive the company’s technical direction and double its revenue in the next three years.

Comprehensive benefits, including:

• Competitive salary and significant bonus potential
• Enhanced pension match with salary sacrifice option.
• Health insurance and life assurance.
• Sabbatical leave after five years.
• 33 days of annual leave (including bank holidays).

Lead Software Developer

Guildford

Paying up to 70,000 (DOE)

Please note that due to the nature of the work, you will need to be eligible to obtain a high level of UK security clearance - Please only apply if suitable.

Responsibilities :

• Developing software for network security applications
• Developing novel signal, image, or data processing applications in C/C++
• Developing user interfaces in HTML/Typescript/JavaScript
• Providing support and training to our customers in using the software
• Providing training, mentoring and leading other more junior team members

Experience required:

• Hold a undergraduate degree or a PhD in a numerate discipline
• Ideally have 3 or more years software development experience, preferably in C/C++
• Be familiar with using and configuring Linux systems.
• have experience in developing and maintaining complex real-world systems
• Have previously used source control systems such as subversion
• Understand the importance of clear, efficient software design
• Ideally have experience working in the in the Aerospace, Military or Defence sectors.

Disclaimer:

This vacancy is being advertised by either Advanced Resource Managers Limited, Advanced Resource Managers IT Limited or Advanced Resource Managers Engineering Limited ("ARM"). ARM is a specialist talent acquisition and management consultancy. We provide technical contingency recruitment and a portfolio of more complex resource solutions. Our specialist recruitment divisions cover the entire technical arena, including some of the most economically and strategically important industries in the UK and the world today. We will never send your CV without your permission. Where the role is marked as Outside IR35 in the advertisement this is subject to receipt of a final Status Determination Statement from the end Client and may be subject to change.

Senior Software Developers specialising in trading systems required for an excellent client based in London.
The successful Software Developer will join a extremely talented development team and you will be exposed to creating and maintaining our client's own applications based around a C#/.NET/SQL Server/ASP.NET universe. Many projects are greenfield projects and allow you to make your own mark on the development process early on.You will be given the opportunity to work with the some of the latest technologies possible and will be expected to produce excellent code for our clients in house software applications and trading platform.
Our client offers a very collaborative working environment with all of the development team coming from excellent educational backgrounds from across Europe. This role is within the sports trading industry so any candidate applying should either have an interest in the industry, or experience within it.
This is predominantly an office-based role. As well as very competitive salaries, our client offers a comprehensive benefits package.

Skills required:

• C#
• Worked with the latest version of the .NET platform
• Database experience - SQL Server
• WPF
• Angular, TypeScript
• Excellent communication skills both written and verbal
  Knowledge of working with trading platforms
• Modelling experience
• High level aptitude for technology
• Education to at least a BSc level or higher in Computer Science or Mathematics from a Russell Group University or equivalent.

Desirable skills:

• HTML5, CSS, JavaScript
• Multi-threaded application development
• Understanding of Windows technologies

If you feel you have the skills and experience required for this opportunity, please contact Oliver Wilson on (phone number removed) or email (url removed)

Spectrum IT Recruitment (South) Limited is acting as an Employment Agency in relation to this vacancy.