Senior Front-End Developer

Job description

Team: Web Engineering

Location: London, UK

Ably is the world’s fastest Data Stream Network (DSN) spread over 14 data centers and 175+ points of presence. Each day we stream billions of realtime messages to millions of end-users for thousands of developers around the world. Some of the things our platform powers: HubSpot’s chat and collaboration products, live score updates for millions of Australian Open tennis fans, live transit updates for three million Chicagoans. Working at Ably means helping to build the infrastructure that will power and shape the future of the internet.

To see what life’s like at Ably, check out our careers page at

What we do

Ably’s engineering team is deeply technical, collectively bringing a wealth of experience and broad technology skills across infrastructure, security, distributed systems, and much more. The calibre of the code we produce is what excites and motivates us each day. If you enjoy solving hard distributed system problems that are mostly platform agnostic and theoretical in nature, then you'll love working at Ably.


In this role:

You will be responsible for hands-on front-end development and assisting the web engineering team to deliver our website, developer dashboards, common web services, and front-end for our provisioning APIs that our customers, developers like yourself, depend on.

You will be successful if you:

  • Primarily like to be hands-on writing front-end code and enjoy collaborating with a team of web engineers. You don’t mind putting your hand to some backend code when necessary.

  • Are passionate about developer experience (a.k.a. user experience), the user interfaces and design of the features you are delivering.  

  • Like to see a feature delivered end-to-end, ensuring the backend code is robust, the test coverage is thorough, and the frontend and developer experience is rich and enjoyable for our customers.

  • Care about code quality and enjoy collaborating with a deeply technical team to solve the hard problems we face providing our distributed messaging system.

Technical skills needed:

  • Front-End markup. A minimum of five years of professional experience as a front-end developer. You must be an expert in HTML, CSS, server-side CSS pre-processors such as SASS, and design patterns for CSS such as BEM. You should have experience converting designs into usable, highly performant and resilient front-end code.

  • Front-end coding. A minimum of five years of professional experience using Javascript (both modern and older ECMAScript version), and be knowledgeable with at least one front-end framework such as React or Angular.  You should be familiar with Webpack.

  • Testing strategies. You must have a strong working knowledge and experience of continuous integration and testing frameworks, using a pyramid approach for all front-end code (unit testing, integration testing, acceptance testing, etc).

Nice to have skills:

  • Ruby. Familiar with Ruby and Ruby on Rails. This is the primary backend framework we use for our website and web applications, so you should be confident working on understanding the Rails framework and making small backend changes.
  • Knowledge of realtime, event-driven and streaming protocols.
  • Experience delivering developer-focussed APIs.

  • Experience with any of the other languages we use extensively at Ably: Node.js, Elixir or Go

  • Our team are active open source contributors and are encouraged to do this as part of their role at Ably.  We like new team members who enjoy contributing back to the open source community, even if those contributions are small. 

  • Good grasp of Agile, Kanban and SCRUM.

What’s it like to work at Ably?

Founded by two engineers who spotted a hard and largely unsolved problem, Ably is, at its heart, an engineering company. To provide the infrastructure required for a high-bandwidth, always-connected world we hire engineers with a broad set of technical skills who are ready and capable of taking on challenging realtime engineering problems.

As a company and engineering team we’re committed to a future internet that’s open and Ably’s engineers contribute to existing open source projects. See 

We want to work in a company of inclusive people who treat each other well. We’re building a company with a diverse set of people who value:

  • Ownership and impact of work. You have real autonomy and ownership over your work with a visible impact inside Ably, and externally on products powered by Ably that you use in your daily life.

  • An environment to thrive. Modern, comfy office in the heart of Old Street. Excellent transport links, lots of great food, bars and restaurants nearby, and multiple work spaces to match your working style.

  • Truly flexible working and not just lip service. We like people to be in the office most of the time, but work should also fit around life and individual ways of working so you’re free to mold hours and environment to your needs.

  • Work is varied and challenging as we’re solving hard, complex problems that push the limits of what’s possible with today’s software and infrastructure.


  • Salary: competitive and negotiable, depending on experience

  • Health insurance

  • Gym membership

  • Regular company away days and social events

  • Weekly team breakfast or lunch

  • Free drinks and snacks in the office

  • Ongoing professional development (training, events, conferences)

  • 25 days of paid annual leave (33 days including bank holidays)

  • Company contributions towards your pension

  • Your choice of high quality tech kit to work on

Ably has a culture that values employee freedom and responsibility. Apply to talk to us to see if this role on an impactful and collaborative team is right for you.