Senior Software Engineer in London

About NexGen Cloud

We are a fast‑growing company building next‑generation GPU cloud infrastructure. NexGen Cloud is the company behind Hyperstack, a cloud platform providing on‑demand and private cloud infrastructure for high‑performance workloads. Hyperstack is used by teams running compute‑heavy applications that need speed, reliability, and control.

AI Studio is Hyperstack’s fastest‑growing product and an end‑to‑end GenAI platform that enables customers to fine‑tune models, evaluate performance, and deploy production inference without managing infrastructure. As adoption grows and workloads scale, we are looking for a Senior Software Engineer to help shape and evolve the core systems that power the platform. In this role, you will take ownership of critical product areas and underlying services across the AI Studio stack, design and build robust user‑facing features, APIs, and backend systems that orchestrate model training, evaluation, and deployment at scale. You will play a key role in shaping technical direction, making architectural decisions, improving system reliability and performance, and raising the quality bar across the codebase.

This is a senior individual‑contributor role for an experienced Software Engineer with a high degree of autonomy and ownership. You will lead the technical design and delivery of complex systems and product areas, from early exploration through production and long‑term maintenance.

What You’ll Be Doing

• System ownership and technical design: Own the design, implementation, and evolution of complex product areas and backend systems. Lead technical design for new features and services, making architectural decisions that balance scalability, reliability, performance, and long‑term maintainability from early design through production and ongoing operation.
• End‑to‑end software development: Build and maintain user‑facing interfaces and backend services/APIs as required by the product, ensuring cohesive end‑to‑end functionality and a strong user experience.
• Code quality: Write clean, maintainable, and well‑tested code. Lead by example in code reviews, uphold and evolve shared engineering standards, and drive improvements to the quality, structure, and maintainability of the codebase over time.
• Documentation: Produce and maintain clear technical documentation for systems, APIs, and features. Help keep internal knowledge bases and relevant user‑facing documentation accurate and up to date.
• Collaboration: Partner closely with Product and Design to shape solutions from ambiguous requirements. Work with engineers across the wider Engineering group to align on architecture, shared systems, and technical standards, and to manage cross‑team dependencies. Communicate technical trade‑offs, risks, and constraints clearly.
• Reliability & performance: Take responsibility for production readiness and operational health. Identify failure modes, improve observability, and drive performance and reliability improvements.
• Technical Leadership: Support and mentor other engineers through collaboration, design discussions, and code reviews, helping raise the overall quality and effectiveness of the team.
• Continuous improvement: Identify high‑impact improvements to architecture, tooling, and processes, and drive initiatives that improve system quality and developer productivity over time.

About You

Essential

• Strong experience designing, building, and operating production backend systems and APIs, with proficiency in Python and frameworks such as Flask.
• Proven ability to own complex asynchronous, long‑running, or resource‑intensive workflows end to end, with a focus on reliability, observability, and operational readiness.
• Experience shipping full‑stack product features using modern web frameworks such as Next.js, with a solid understanding of frontend and backend integration.
• Practical understanding of AI Studio style workflows in production, such as model training or fine‑tuning orchestration, evaluation, deployment, and inference.
• Strong system design and architecture skills, including API design, service boundaries, security, and data systems (SQL and NoSQL), and managing versioned or long‑lived resources.
• Strong production ownership, including monitoring, debugging, incident response, and driving improvements based on real‑world usage.
• Experience with modern development and deployment workflows, including Git, CI/CD, Docker, and Kubernetes.

Nice to Have

• Hands‑on experience with LLMs, generative AI systems, or fine‑tuning workflows, including using or integrating model APIs and serving frameworks.
• Experience building AI platform capabilities such as model versioning, evaluation tooling, deployment safety, monitoring, and observability for model performance and drift.
• Exposure to GPU‑intensive or distributed workloads, including performance tuning, capacity considerations, or cost‑aware system design.
• Experience building developer platforms or internal tooling that supports experimentation and rapid iteration, such as workflow‑driven systems, job orchestration, or data tooling.
• Contributions to open‑source projects or personal projects in the AI, ML infrastructure, or developer tools space.
• Curiosity about emerging AI tools and best practices, and a track record of quickly learning and applying new technologies in a fast‑evolving space.

What We Offer

• Competitive salary and annual discretionary bonus scheme.
• Employee well‑being benefits.
• 25 days of holiday, plus public holidays.
• Flexible working arrangements (remote or hybrid, depending on role and location).
• Real ownership and autonomy, with the trust to take initiative and experiment.
• The opportunity to make a visible, meaningful impact as we scale.
• Clear career progression and growth opportunities in a fast‑growing company.
• A collaborative, international culture built on trust, transparency, and ownership.
• The chance to help shape NexGen Cloud’s team, culture, and future alongside ambitious, mission‑driven colleagues.

Want to do a little more research before you apply? Head over to our NexGen Cloud careers page to view current openings and follow us on LinkedIn and X to learn more about our journey, newest releases and hear exciting news in the neocloud space.