Lead Software Engineer, Full-Stack Developer in London

We value your talents, traditions, and uniqueness—and we’re committed to fostering a strong sense of belonging in a respectful workplace. We believe that belonging leads to better outcomes and a stronger community of associates united by our mission. Integrity, Client Focus, Diverse Perspectives, Long-Term Thinking, and Community.

Your performance will be reviewed annually, and your compensation will be designed to motivate and reward the value that you provide. You’ll receive a competitive salary, bonuses and benefits. Your company-funded retirement contribution will factor in salary and variable pay, including bonuses.

Enjoy generous time-away and health benefits from day one, with the opportunity for flexible work options. Receive 2-for-1 matching gifts for your charitable contributions and the opportunity to secure annual grants for the organisations you love. Access on-demand professional development resources that allow you to hone existing skills and learn new ones.

As a Software Engineer - Lead, you will be responsible for seeding and growing the AI Engineering function within GCG technology. You will partner with business partners and AI engineers to turn ambiguous problems into working AI solutions that improve our client-facing capabilities and business outcomes. You will be responsible for end-to-end development including and surrounding our AI applications. You are the build-and-deploy bridge between the people who own the problem and the AI platform that powers the answer: you lead discovery, design the approach, write the code, and own it in production.

You will operate as a player-coach, not a distant manager, working at the intersection of AI, software, and data. This is a hands-on engineering role for someone who is as comfortable in a working session with a business team as they are building a retrieval pipeline or hardening an agent. As a lead engineer, you will also be responsible for coaching and mentoring others within the GCG organisation as we strive to become an AI-first organisation. You will help set the standard for how generative AI gets built and operated responsibly at scale across the firm.

You will hire, structure, and develop a team of AI/ML and agentic software engineers. Set the bar for technical quality and the culture you want them to work in. Design, build, and operate production generative AI applications such as copilots, assistants, knowledge-search experiences, and agentic workflows, as reliable, production-grade systems rather than demos. Lead from inside the work, not above it, including engineering capabilities and writing code as appropriate.

Practice eval-driven development: define acceptance criteria up front, build evaluation harnesses, and measure correctness, latency, and hallucination so quality is verifiable and regressions are caught before production. Apply FinOps and cost-optimisation practices to AI workloads, tracking and managing token, inference, and infrastructure spend so solutions stay cost-effective as they scale. Integrate AI solutions with enterprise data systems, APIs, and MLOps/LLMOps tooling, applying sound system design and distributed-systems judgment.

Apply responsible-AI judgment proportionate to the risk of each use case, working with risk and compliance partners to build the controls, human-oversight patterns, and audit trails that let the firm move quickly and safely. Partner with InfoSec and data-governance teams to meet regulatory and internal-policy requirements such as SOC 2 and applicable data-privacy regulations. Codify what works into reusable tools, patterns, and playbooks, and feed insights back to platform, product, and engineering partners so the whole organisation gets faster.

Demonstrate the ability to be a full-stack engineer and versatility across different development platforms.

Required qualifications:

• Substantial experience leading software, platform, cloud, or data engineering teams, including building a global team or function from an early stage.
• Practical experience applying AI or machine learning to real business problems, ideally including agentic or LLM-based systems.
• Strong grasp of modern platforms: cataloguing and metadata, semantic and context layers, and data quality across structured and unstructured data.
• The right to work in the UK and the ability to work from London on a hybrid basis.
• Open to travel and work across time zones (particularly the US).
• Hands-on production experience building and shipping LLM-powered applications, including advanced prompt engineering, retrieval, agent development, and evaluation.
• Strong understanding of system design, APIs, distributed-systems concepts, and cloud-native development, with a track record of owning production systems on solid architectural foundations.
• High agency and comfort navigating the ambiguity of a large, regulated organisation, with the judgment to make trade-offs between scope, speed, and quality.
• Bachelor’s degree in Computer Science, Engineering, or a related technical field, or equivalent practical experience.
• Experience implementing security, privacy, and compliance controls in production systems, for example IAM, encryption, audit logging, and data-governance practices, ideally in a regulated environment.

Preferred qualifications:

• Background in financial services or another regulated enterprise environment.
• Experience with vector databases (for example pgvector, Pinecone, Weaviate, or Chroma) and agent or orchestration frameworks (for example LangChain, LlamaIndex, or the Model Context Protocol).
• Experience with MLOps/LLMOps tooling such as experiment tracking, model versioning, monitoring, evaluation/observability platforms, or CI/CD for ML and LLM systems.
• Experience implementing responsible-AI or AI-governance controls such as guardrails, human-in-the-loop oversight, and audit trails in production.
• You hold high standards for code quality, testing, clarity, and reliability, and you apply engineering judgment to know which standard matters where.
• You can say no constructively by pushing back on scope, proposing better alternatives, and protecting quality and team capacity when it counts.
• You stay current as the tooling and model landscape shifts, and you help the people around you do the same.

If this role isn’t what you’re looking for, check out our other opportunities and join our talent community.

In addition to a highly competitive base salary, per plan guidelines, restrictions and vesting requirements, you also will be eligible for an individual annual performance bonus, plus Capital’s annual profitability bonus plus a retirement plan where Capital contributes 15% of your eligible earnings.

We are an equal opportunity employer, which means we comply with all federal, state and local laws that prohibit discrimination when making all decisions about employment. As equal opportunity employers, our policies prohibit unlawful discrimination on the basis of race, religion, color, national origin, ancestry, sex (including gender and gender identity), pregnancy, childbirth and related medical conditions, age, physical or mental disability, medical condition, genetic information, marital status, sexual orientation, citizenship status, AIDS/HIV status, political activities or affiliations, military or veteran status, status as a victim of domestic violence, assault or stalking or any other characteristic protected by federal, state or local law.

Summary Location: London Type: Full time