Lead SDK Developer

Job description

Location: London, UK

Salary: £70k to £95k

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 www.ably.io/careers.

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

Clients interact with Ably’s cloud service, for the most part, using client library software that is written and maintained by Ably. Libraries exist for most major platforms for both clients and servers (see https://www.ably.io/download).

You will be responsible for managing the maintenance and ongoing development of all libraries going forward. This will include owning and maintaining a number of libraries personally, plus managing development and maintenance of libraries by external developers.

You will be an important point of contact with customers and therefore will have a significant bearing on our reputation; therefore you must be both professional technically very proficient.

You will be successful if you:

  • Together with stakeholders in engineering and developer relations, maintain a develop the client library API and specification in response to new feature developments, target platform evolution, and other issues.

  • Maintain the compliance matrix of all libraries against the specification.

  • Manage the full lifecycle of client library development, maintenance and test.

  • Be responsible personally for at least two of the principal libraries, including at least one of iOS/cocoa and android/java.

  • Develop and maintain relationships with external developers for work on libraries that are not maintained internally, and management of the associated budget.

  • Together with stakeholders in developer relations and engineering, formulate API proposals and specifications for new features, including liaison with customer technical representatives where applicable.

  • Together with stakeholders in developer relations and engineering, contribute to the development of developer documentation.

  • Provide second-level support to the Ably customer/developer communities to resolve issues raised against the libraries.

  • Be responsible for the creation and maintenance any forks of third-party libraries that are necessarily created as a result of library development, and work on upstreaming any changes that Ably makes.


Technical skills needed:

  • Languages: you must have broad software development experience across a range of languages, including a minimum of three years of professional experience with at least one of Android or iOS. Expertise in at least one additional language from Go, Ruby, .NET, nodejs is also required.

  • Networking and protocols: you must have a very strong understanding of networking and protocols generally, HTTP and ideally have direct development experience of writing protocol software.

  • Open source: You should be able to demonstrate a track record of participation in and contribution back to the open source community, even if those contributions are small. 

  • Leadership and management: you must be able to oversee external contractors working on our libraries, including both both administrative and technical oversight; PR review; planning and budgeting; contractor evaluation and selection.

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 https://go.ably.io/open 

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 Camden. Excellent transport links, Camden Food Market with over 100 food stalls and restaurants, and multiple work spaces to match your working style.

  • Truly flexible working and not just lip service. Come into the office, work at home, or rock up at your local coffee shop at the hours you focus best.

  • 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.


  • 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.