Senior Software Engineer in London

We are looking for a Senior Software Engineer who thrives on turning ambitious ideas into production systems that delight developers and deliver real business impact. You will work across the stack, from backend APIs and orchestration to SDKs, dashboards, and developer tools. You will take ownership from start to finish, understanding user needs, designing elegant solutions, and delivering outcomes that make building with AI faster, simpler, and more creative. You will collaborate across the company to build systems that are robust, performant, and a joy to work on. This role combines technical depth, product intuition, and leadership, making it ideal for engineers who want to shape both how things are built and why they matter.

Is this role a fit for you?

• You are motivated by impact.
• You thrive on transforming complex AI systems into products that developers love to use.
• You think holistically about architecture, user experience, and business outcomes, and you take pride in delivering systems that are both elegant and dependable.
• You are equally comfortable designing APIs, building scalable backend services, and improving developer-facing experiences.
• You set a high bar for quality, mentor others to reach it, and drive alignment between product ambition and technical reality.

What this role could entail:

• Lead the design and implementation of core systems powering Runware's AI platform.
• Build and evolve backend APIs, SDKs, and developer tools that make AI integration seamless.
• Integrate and optimise image and video models while supporting new modalities such as audio and custom LLMs.
• Architect scalable, reliable systems for inference orchestration and workload optimisation.
• Partner with platform and infrastructure teams to drive performance, reliability, and observability improvements.
• Shape technical direction through architectural discussions and long-term planning.
• Mentor engineers through code and design reviews, fostering technical excellence and growth.
• Contribute to documentation, tooling, and SDKs that enhance the overall developer experience.
• Drive initiatives that improve how we build, deploy, and maintain our platform.

Requirements:

• Deep experience building distributed and high-performance systems.
• Strong programming skills in PHP, Python, TypeScript, or similar.
• Proven track record of designing and delivering scalable backend systems and APIs.
• Understanding of asynchronous workloads, queues, and streaming data.
• Experience working with cloud and bare-metal infrastructure.
• Excellent grasp of system design, performance optimisation, and scalability principles.
• Clear communicator who leads technical projects and collaborates effectively across teams.
• Passionate about mentoring others and raising engineering standards.
• Proactive problem-solver who balances short‐term progress with long‐term vision.

We are a remote‐first collective, meeting in person twice a year to plan, brainstorm, celebrate wins, and enjoy some face‐to‐face time. We have core hours for cooperative working and calls, but outside of that your calendar is yours. Work the hours that let you perform at your peak while also building a healthy life. Our release cycles are fast and intense, but they are followed by real downtime. After big pushes we expect the team to unplug, recharge, and come back ready and stronger than ever for the next leap.

Benefits:

• Generous paid time off – vacation, sick days, public holidays.
• Meaningful stock options – share in the upside you create.
• Remote‐first setup – work from home anywhere we can employ you.
• Flexible hours – own your schedule outside core collaboration blocks.
• Family leave – paid maternity, paternity, and caregiver time.
• Company retreats – twice‐yearly gatherings in inspiring locations.

Please note: We are unable to offer visa sponsorship in the UK at this time. Candidates must have existing right to work in the UK.