Mid-Level Full Stack Developer, QuantSpark
Security clearance required
£45-55k
2 days a week in office (Southwark )
QuantSpark is revolutionising how data and AI serve society
Open for applications
QuantSpark is revolutionising how data and AI serve society
21-100 employees
Open for applications
£45-55k
2 days a week in office (Southwark )
21-100 employees
Company mission
Strategy consultancy meets product studio: We build AI-powered tools that turn data into decisive competitive advantage.
Role
Who you are
- Candidates must be eligible for Security Clearance
- 1–3 years of progressive full-stack engineering experience (commercial/professional)
- 1+ year of commercial experience with a Python backend framework (FastAPI/Django/Flask) and JavaScript or TypeScript (ideally React)
- Experience building and consuming REST APIs and developing modern web UIs
- Strong understanding of Git and common branching / PR workflows
- Familiarity with at least one database system: PostgreSQL, MySQL, MongoDB (schema design and basic query performance awareness)
- Demonstrated ability to solve problems independently and deliver reliable features
- Strong communication skills—comfortable collaborating async and in teams
- Hands-on experience using AI coding agents in day-to-day development (prompting, iterative refinement, reviewing generated code, and validating outputs)
- Practical understanding of core AI Engineering concepts, such as:
- LLM fundamentals and limitations (hallucinations, context limits, evaluation mindset)
- Prompting patterns and tool use (function calling/tool invocation concepts)
- Basics of RAG (retrieval-augmented generation) and embeddings at a conceptual level
- Safety/privacy awareness when using AI tools (secrets, PII, licensing concerns)
- Ability to integrate AI assistance into an engineering workflow while maintaining code quality (tests, reviews, reproducibility)
Desirable
- Experience with async Python, background jobs/queues (Celery/RQ), and API auth (JWT/OAuth)
- Frontend state management and UI patterns (React Query, Redux, component libraries)
- Docker, CI/CD, cloud fundamentals (AWS/GCP/Azure), and basic observability (logs/metrics)
- Exposure to integrating LLM features into products (e.g., OpenAI/Anthropic APIs), basic evaluation, and prompt/version management
What the job involves
- Reports to: Engineering Manager
- At QuantSpark, we're transforming how data and AI serve society. Our team partners with forward-thinking organisations across multiple sectors to harness the power of analytics and artificial intelligence, creating meaningful impact that extends far beyond financial outcomes
- In addition to serving our consulting clients, we also develop proprietary SaaS products tailored for B2B applications across a range of industries
- You'll build and maintain full-stack web features using Python backend frameworks (e.g., FastAPI/Django/Flask) and React (JavaScript/TypeScript)
- Design, develop, and document RESTful APIs; integrate them with responsive, accessible UIs
- Work with product and design to turn requirements into well-scoped technical solutions
- Write clean, testable, maintainable code and contribute to code reviews and engineering standards
- Use AI coding agents (e.g., GitHub Copilot, Cursor, Claude/ChatGPT-based workflows, etc.) to accelerate delivery while ensuring correctness and security
- Help improve development workflows (DX), including tooling, CI/CD, linting, testing, and observability where relevant
- Work Alongside Brilliant Minds: Collaborate with exceptionally talented colleagues who bring diverse expertise from leading universities, top tech companies, and varied industry backgrounds—all united by intellectual curiosity and a drive to solve meaningful problems
- Innovate with Purpose: Explore cutting-edge approaches to analytics engineering, from modern data stack implementations to GenAI tooling, ensuring QuantSpark stays at the forefront of the industry
Application process
- 30 min screening call with Talent partner
- Short take home technical test
- 1 hour onsite interview
- 45 min virtual culture interview
Salary benchmarks
Our take
QuantSpark helps governments and businesses to strategically apply data science through the development of complex decision-making software. Primarily, its work involves analysing large datasets and systems in order to understand customer behaviour and help clients make informed decisions for strategic planning in sales and marketing.
In recent years, big data has become central to the operation of businesses large and small, and this has led to great demand for data scientists fluent in sophisticated modelling and analysis. QuantSpark seeks to go a step further, providing a service which combines data science with commercial insight- effectively providing both services through one transaction. By doing this, QuantSpark hopes to offer clients a more meaningful insight into their data than a standard consultancy could.
Already, the company has an impressive client list, including the UK Government, the Australian Government and Bain Capital. QuantSpark's tools and solutions are developed to become embedded in its clients' operations, ensuring a long-lasting relationship between them, and meaning that, as QuantSpark continues to expand its client base, its model should allow it to see continued success in the future.
Steph
Company Specialist at Welcome to the Jungle
Company
Company benefits
- Tech for good: We are passionate about giving our team the chance to have a real social impact and will have the opportunity to work on a wide variety of impactful projects
- Training budget: Everyone in QuantSpark has £6,000 training budget and 12 ring-fenced days a year to spend on their own professional development
- Work abroad for up to 1 month per year
- Generous EMI Share Options scheme
- Socials, clubs and guilds to connect with colleagues and share knowledge
- Hybrid working (2-3 days in office per week)
- Dog friendly office
- Cycle to work scheme. Onsite showers
- 25 days annual leave + bank holidays + buy/sell 5 days annual leave
- Pension matched up to 6%
- Vitality Private healthcare
- Annual performance bonus: Company profit share scheme and a personal performance bonus of 10%
Company values
- Problem Solving Power: We thrive on solving the biggest challenges with data, strategy, and AI - delivering clarity from complexity.
- Innovation That Lasts: We go beyond solutions - reimagining operations and scaling impactful innovation across industries.
- Results That Matter: We focus on outcomes that count - driving efficiency, profitability and positive societal impact.
Company HQ
London, UK
Articles
Leadership
Adam Hadley
(Co-Founder & CEO)Entrepreneur and CBE Adam leads QuantSpark and Tech Against Terrorism, using AI and analytics to tackle global challenges, strengthen security, and foster economic growth in the UK.
Diversity, Equity & Inclusion at QuantSpark
- As an AI-first consultancy tackling complex challenges from economic crime to government fraud prevention, we know that diverse perspectives drive better solutions. Different backgrounds, experiences and ways of thinking aren't just nice to have—they're essential to building technology that works for everyone and solving problems others miss.
- Transparent progression frameworks ensuring fair opportunities for growth regardless of background
- Inclusive recruitment practices designed to attract talent from underrepresented groups in tech and data science
- Regular culture initiatives like our peer feedback sessions, workshops and AMA's where we actively shape our workplace together
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