AI Engineer

Type: Full time, Permanent

Location: Blackfriars, London, 2 days working from our headquarters

Seniority: Mid to Senior (SFIA 4)

SC Eligibility Required: You do not need to already hold Security Clearance, but you must be eligible to undergo the vetting process.

About Us

QuantSpark applies data, analytics, and AI to commercial and societal problems that genuinely matter — for financial services, public sector clients, major retailers, international clients and many well-known UK businesses. Our work sits at the intersection of data science, software engineering, and client delivery. The projects are varied, challenging and hugely impactful - what we build often goes live in weeks.

We're a 50-person boutique consultancy headquartered in Central London. Small enough that your judgment shapes outcomes; large enough that you'll work across multiple sectors and problem types in your first year. We invest heavily in our people, give genuine ownership, and expect high engineering standards. That means the opportunity to shape important work, the support to keep learning, try new things, and the trust to do your best work without unnecessary bureaucracy.

The Role

We’re looking for an AI Engineer who has already moved from experimentation into production and wants to go further. You may have started in data science or Machine Learning, but now you’re happiest building reliable systems: shipping LLM-powered applications, designing evaluation frameworks, creating retrieval pipelines, and making sure things keep working when real users, messy data, and changing requirements get involved.

At QuantSpark, you'll apply that foundation to real client problems. Some engagements call for a carefully orchestrated AI pipeline; others need a well-chosen low-code tool wired up properly. The skill is knowing which approach fits the problem, making it work reliably, and creating measurable impact for the client.

What You'll Be Doing as an AI Engineer at QuantSpark

• Lead delivery on client engagements. You'll own the technical shape of AI and ML workstreams from scoping through handover — making the build-versus-buy-versus-wire-together call, and being the engineer the client trusts in the room.
• Help us win the next engagement. You'll work alongside our Consulting team on live opportunities — translating client problems into credible technical approaches, running discovery sessions, and shaping proposals that are honest about what AI can and can't do.
• Build automation that lands. From orchestrated AI pipelines to a well-wired Power Automate flow, you'll deliver the solution that actually solves the client's problem.

The Problems You'll Solve

In a typical year you might be:

• Turning a PE-backed business's unstructured operational data — contracts, claims, supplier correspondence — into a usable signal, and building the systems that keep doing it.
• Working with a public sector team on fraud detection or predictive maintenance, with the rigour and traceability those clients need.
• Designing an agentic workflow that compresses a week of manual analyst work into hours, with guardrails the client can trust.
• Replacing a brittle Power Automate flow with something better — or building the right one because that's actually what the problem needs.

What You’ll Build

• Production LLM applications — RAG, retrieval pipelines, prompt-engineered workflows, with the evaluation work that makes them reliable.
• Multi-agent systems — tool use, orchestration, memory, and guardrails that keep autonomy useful.
• Classical ML in production — forecasting, classification, optimisation, because not every problem needs a transformer.
• Low-code and workflow automation — Power Automate, n8n, used deliberately when they're the right tool.
• AI harness tooling — Claude Code, Codex, and the broader AI development toolchain.

Most consultancies make engineers pick a lane, we feel our hybrid approach is a better match for the problems clients bring us.

Who You’ll Work With

You’ll sit within our Engineering team and work day-to-day with Product & Consulting and client stakeholders. We’re a genuinely curious, low-ego bunch who care about doing meaningful work. We keep that culture deliberate — internal guilds, lunch-and-learns, regular talks and events in the office, and hackathons where you'll build a career alongside peers from across the business.

You Should Hit Apply If

• You've crossed the line from experimentation to production. You've shipped LLM-powered applications and lived with the consequences — edge cases, latency, prompt drift, keeping things working when context gets messy.
• You bring ML rigour to AI engineering. Evaluations, model quality, monitoring, drift detection. You don't just ship — you measure.
• You've designed RAG and agentic systems with intention. You understand chunking, retrieval quality, context management, and where these systems break under real conditions.
• You're comfortable across the modern AI toolchain. Claude Code, Codex, Power Automate, n8n. Pragmatic about choosing the right tool.
• Your code is production-quality. Clean, testable, version-controlled. You collaborate effectively with software engineers without needing translation.
• You treat client problems as your own. Commercially aware, comfortable with the “why,” and you'd rather over‑own a difficult delivery than hide behind process.
• You communicate clearly. You can explain trade‑offs to non‑technical stakeholders and push back constructively when requirements don't make sense.

Nice to have: experience in regulated environments (financial services, public sector); MLOps practice; pre‑sales or technical proposal experience; familiarity with responsible AI practice.

Why QuantSpark

• Variety of work. You'll work across sectors but see engagements through — most engineers are on one or two engagements at a time.
• Engineering quality is taken seriously. Evaluations, monitoring, code review that catches things before they hit clients.
• Real investment in you. £6,000/year for training, upskilling and conferences — one of the most generous budgets in the market. EMI share options to share in the reward as we grow.

Perks & Benefits

• Financial upside: Up to 10% personal performance bonus. Company profit share, distributed equally to everyone annually. EMI share options for every team member, regardless of seniority. Pension up to 12% total contribution via Nest.
• Investing in your career: Market leading £6,000 per year personal learning and development budget. Protected training days when not on live engagements. Tuition support for part-time Masters, ML/AI certifications, and professional qualifications. Transparent Growth tracks and opportunities.
• Health, taken seriously: Full Vitality private healthcare, including in‑patient, GP, dental, optical, and advanced cancer cover. 8 talking therapies sessions per year. 24/7 EAP and a 12‑month Headspace subscription. Up to 50% off Nuffield, Virgin Active, PureGym, and Active Rewards perks.
• Time to live a full life: 33 days off, including 25 days annual leave plus 8 bank holidays. Buy or sell up to 5 days each year. Work from abroad for 4 weeks every year. Sabbatical up to 6 months after 3 years’ service.
• Family-friendly, properly: Enhanced maternity and paternity leave. 3 sessions of maternity coaching via The Maternity Coach. Shared parental leave and enhanced bereavement leave.
• Recognition and the everyday: Quarterly team socials. Peer-nominated awards with vouchers. Scaling anniversary fund on every work anniversary. Cycle to Work scheme up to £2,500. Monday breakfasts, regular talks & events in the office, hackathons, and clubs.

Equal Opportunities

We're committed to building a diverse and inclusive team. Different perspectives, identities, and experiences make us stronger. All qualified applicants will be considered regardless of sex, sexual orientation, marital status, race, nationality, religion, disability, or age.