Senior Software Engineer, Backoffice Platform

Responsibilities

You will own and manage the back-office platform, including customer entitlements, billing systems, and internal tooling for Finance and Support teams. You will partner across departments to design solutions, champion AI-assisted development, and ensure high standards for system observability and testing.

Requirements

The ideal candidate has experience working in large, established codebases and a track record of shaping architecture within inherited systems. You should possess an AI-first mindset, the ability to work through ambiguity, and strong judgment regarding when to extend or replace existing systems.

Skills

• Ruby on Rails
• Software architecture
• System design
• Billing systems
• Internal tooling
• AI-assisted development
• LLMs
• System observability
• Test strategy
• Data ownership
• Infrastructure management
• API development
• Technical leadership
• Problem solving
• Communication

Benefits

• Equity
• 28 days of paid annual leave
• Enhanced parental leave
• Home workstation budget
• Personal learning and development budget
• Private healthcare
• Medical cash plan
• Mental wellbeing coaching
• Wellbeing budget
• Life assurance
• Income protection
• Tech scheme
• Cycle to work scheme

About this role

Our everyday digital experiences are in the middle of a realtime revolution: chatting alongside a livestream, getting realtime financial updates, or working with colleagues in a shared online space. Consumers now expect realtime as standard, and Ably powers a large part of it.
We put developers first. Our products help teams build, extend, and deliver realtime digital experiences, delivering over 700 billion messages to more than 2 billion devices every month. Teams at HubSpot, Fin, Dialpad, NASCAR, Sportsbet, and General Motors all build on Ably.
Working at Ably means helping build the infrastructure that will shape the next generation of the internet. More of what people do online is becoming live, shared and interactive, which only makes what we build more relevant and more necessary. AI is the latest place that shows up. There's still so much to build, and we'd like your help with it.
About this role
Ably's back office platform is where every customer account is managed. It holds the packages, entitlements and limits that determine what each of our customers can do, and it runs the tooling our Finance, Customer Success and Support teams rely on every day.
This is an opportunity to take ownership of a platform the whole business depends on, with the scope to decide how it should work rather than maintain someone else's decisions. You'll be hands-on across entitlements, administration tooling and billing, working closely with our Head of Infrastructure and our Developer Experience team, and directly with the teams who use what you build.
We work in an AI-first engineering culture: AI tools are part of how we plan, prototype, and iterate, though engineers own every technical decision, and human judgment is the quality bar that everything is measured against.
Day to day you will
Run the back office platform. You'll look after the systems holding every customer's packages, entitlements, limits and billing, along with the tooling Finance, Customer Success and Support use daily.
Solve problems, not tickets. You'll be handed a problem, usually described by the people living with it rather than specified in advance, and you'll own the design as well as the delivery.
Make admin work for the people who use it. Staff should be able to see what a customer has bought, how they're billed and what limits they have, make a change, and trust the result, without needing to understand our internal models.
Partner across the company. Finance, Customer Success, Support and Engineering are all your users. You'll learn their processes well enough to question a requirement rather than just build it.
Champion AI-assisted development. You'll use LLMs and AI tools for planning, spikes, code and docs to accelerate velocity, while owning correctness and architectural quality yourself.
Make the systems explain themselves. Why a customer has the limits they have, and what produced an invoice, should be answerable without an engineer digging through code.
Set the testing bar. You'll decide what good looks like where mistakes cost money, build the harness to match, and hold the line on production readiness.
We'd love to talk if you have
Experience working in large, established codebases, and the judgement to tell when a system should be extended, reworked, or replaced outright, including the confidence to say so unprompted. Ruby on Rails will help you get to grips with what we have today, though we care more about your range than any one language, and what you build here may well not be Rails.
A track record of shaping architecture inside a system you inherited, including the data ownership decisions that come with drawing a boundary.
The ability to self-start, work through ambiguity, and make good decisions without a lot of hand-holding. We'll bring you problems, not designs, and we'd expect you to push back when the answer is to change a process rather than write code.
An AI-first mindset. You see LLMs and AI tools as productivity multipliers and know where to apply the rigour they can't provide themselves.
Experience making systems observable and testable. You instrument what you own, use it to answer questions you never designed for, and have set a test strategy for a system with patchy coverage.
Bonus points if you have
Experience of usage-based billing systems, whether built in-house or on a platform such as Orb, Metronome, or Chargebee.
A background in platform or internal tooling teams rather than product teams.
Experience being the engineer accountable for a system rather than one contributor among many, particularly one subject to financial or compliance audit.
What’s it like to work at Ably?
You'll join a team of around 60 people, working directly alongside senior engineering and leadership. No layers, no bureaucracy, and real ownership from day one.
Remote-first
We hire the best people wherever they are across the UK and Europe, trust them to own their work, and share decisions and feedback openly. Twice a year, in February and August, we all meet in person, and we expect everyone to be there.
Remote-first comes with trade-offs. On one side: flexibility, no commute, long stretches of focus time, and a wider pool of people to hire from. On the other: it can feel isolating, relationships take effort to build, and you miss the chance conversations an office creates. As our only recruiter, you'll need to manage your own time and stay close to the hiring managers and candidates you work with.
If you do your best work with trust and autonomy, this will suit you. If you'd rather have an office around you every day, it probably isn't the right fit.
Our six values shape how we work day to day:
Open for all. We default to sharing openly: source, decisions, and feedback, with open minds to match.
Tech needs humanity. We build with empathy, for colleagues and developers alike.
Even the best do better. We keep raising our own bar, driven by curiosity, not complacency.
Bias for action. Once we know enough to act, we ac...

About Ably (UK)

Technology, Information and Internet · 51-200 employees · headquartered in London, England · founded 2016