Principal Software Engineer (London)

Principal Software Engineer (London)

London Full-Time 70000 - 90000 £ / year (est.) No working from home possible

At a Glance

  • Tasks: Lead innovative software projects and mentor teams while driving impactful solutions.
  • Company: Join a forward-thinking tech company that values collaboration and growth.
  • Benefits: Enjoy competitive pay, extensive learning opportunities, and flexible working arrangements.
  • Other info: Dynamic work environment with a focus on personal and professional development.
  • Why this job: Make a real difference in tech by shaping the future of software engineering.
  • Qualifications: 10+ years of experience in software engineering and strong leadership skills.

The predicted salary is between 70000 - 90000 £ per year.

Principal Engineer

Who You Are

You’ve shown long-term repeated success on a variety of projects, typically over the course of 10+ years.

You are a trusted expert and leader, often called upon to guide ambiguous initiatives and architect scalable solutions.

You bring a blend of deep consulting acumen, technical expertise, and product thinking that drives measurable and impactful outcomes.

In your previous experience, you have

  • Built and shipped production‑grade platforms: the reusable foundations, tools, infrastructure, and workflows that help other teams shift faster and more reliably
  • Taken AI and agentic systems from prototype to production, with a strong understanding of infrastructure, authentication, and observability
  • Delivered on high‑stakes consulting engagements across multiple language paradigms, stacks, ecosystems, and client industries
  • Built high‑quality, maintainable software collaboratively, incrementally, and through an approach tailored towards the unique needs of the clients you’ve served
  • Led the development and delivery of production‑grade software using a variety of languages and frameworks, including but not limited to: Java, C#/.
  • NET, Python, Type Script, Java Script, React, Go, Ruby, Scala, R, and SQL
  • Actively experimented with AI development tools and translated that experimentation into faster, higher‑quality delivery for your teams
  • A track record of understanding, assessing, and embracing new tooling and trends within the software industry
  • Built or integrated AI/ML features into products and systems, including recommendation engines, NLP, computer vision, predictive analytics, RAG pipelines, and agents
  • Successfully led modernisation and replatforming efforts to align legacy systems with short and long‑term business needs
  • Led and delivered solutions to architecture‑level problems including scalability, security, reliability, performance, maintainability, and observability
  • Facilitated alignment across technical and non‑technical stakeholders to move initiatives forward through ambiguity and complexity
  • Provided mentorship and team support at scale, while sharing knowledge and improving team practices
  • Collaboratively led stakeholders to balance technical considerations with product and user needs
  • Actively sought out and effectively given feedback
  • What You’ll Do At 8th Light

As a go‑to technologist and strategist within 8th Light, you’ll work with a variety of clients, typically one to two in a year, while continuing to deepen your and our collective domain expertise over the course of your career with us.

You’ll be responsible for

  • Rapidly building trust with clients, demonstrating technical expertise and understanding of their domain and objectives
  • Driving platform engineering work at the client level, connecting long‑term technical vision to what ships
  • Leading platform strategy and delivery across diverse platform types, connecting long‑term vision to what ships
  • Working pragmatically to balance technology choices while delivering high‑quality work within deadlines
  • Advising clients on architecture, scalability and platform evolution, connecting technical decisions to product and business outcomes
  • Collaborating on systems that involve the full ML lifecycle from data ingestion and preprocessing, to model deployment, integration, and performance monitoring
  • Driving innovation by proactively surfacing new technical approaches and product solutions
  • Leading or initiating formal feedback conversations with teams and clients via retrospectives
  • Clearly articulating and documenting outcomes and driving forward action items
  • Contributing to the health of your team and 8th Light’s culture by modeling our Values
  • Designing and managing high‑level technical roadmaps for large engagements
  • Building your network and maintaining relationships with clients and other industry leaders within your domain
  • Coaching client engineering teams, transferring knowledge and leveling up practices
  • Influencing client CTOs and executive decisions.

Planning and execute technical work that involves stakeholders outside of project boundaries such as across a client's technical organization

  • Partner with account teams on planning, opportunity identification, stakeholder relationships, and pre‑sales scope shaping
  • Facilitating retrospectives, strategy sessions, and technical deep‑dives to improve team and project outcomes
  • Identifying, mitigating, and resolving blockers to team progress
  • Contributing to 8th Light by serving as a mentor, leading or designing workshops internally or for clients, representing 8th Light in the tech community, or supporting our hiring processes
  • Demonstrating leadership in scalable system design, modular architecture, and platform‑oriented development
  • Bringing depth in testing strategies, observability, fault tolerance, and secure engineering practices
  • Applying architectural patterns to evaluate tradeoffs and drive clear, documented design rationale
  • Strongly Preferred Skills

We work across many areas, and encourage anyone with the experience listed above to apply.

  • We would particularly like to encourage applicants with experience in the following areas:
  • Platform engineering: building reusable software foundations, internal developer platforms, and infrastructure that other teams build on
  • Data Engineering: including platforms like Databricks for data processing and analytics
  • Delivering production agentic systems, including RAG pipelines, vector search, and agentic frameworks such as Lang Chain, Llama Index, Crew AI, Auto Gen, and n8n
  • Dev Sec Ops & Dev Ops
  • MLOps
  • Infrastructure as Code
  • How You’ll Be Supported

At 8th Light, we believe our people are our greatest asset. Their growth, well‑being, and success shape our future.

  • Our wellness package is designed with the Whole YOU in mind and includes:
  • A robust L&D programme featuring unlimited access to thousands of books, courses, and expert‑led training on the O'Reilly learning platform.
  • Annual financial stipend and time allotment for learning & development
  • Coworking support for our global team
  • 12 weeks of new parent leave available for eligible employees

See our full list of Benefits.

A Note on Compensation

At 8th Light, we are committed to a compensation philosophy that is transparent, fair, and helps us attract and retain top talent in alignment with our company’s strategic growth goals and clients’ needs.

We benchmark our salaries using Geographic Structures to establish competitive pay ranges within the regions where 8th Light’s live.

Our pay ranges for our Principal Engineer position within London is: £92-818-£116-122 GBP

Reach out to for more relevant information pertaining to your local market.

#J-18808-Ljbffr

Principal Software Engineer (London) employer: 慨正橡扯

At 慨正橡扯, we pride ourselves on being an exceptional employer that champions innovation and collaboration in the field of Behavioral Economics and Retirement Research. Our hybrid working model not only offers flexibility but also nurtures a vibrant work culture where employees are encouraged to grow and develop their skills through meaningful projects and leadership opportunities. Join us in Europe, where your expertise will directly contribute to enhancing investor outcomes and shaping impactful business strategies.

Contact Details:

慨正橡扯 Recruitment Team

We think you need these skills to ace Principal Software Engineer (London)

Platform Engineering
AI/ML Integration
Software Development
Java
C#/.NET
Python
TypeScript