Senior Full Stack Engineer

Senior Full Stack Developer

Reporting to:
Engineering Manager
Office Environment:
Hybrid (minimum two days per week)
Type:
Full time, permanent

Skip the queue. Shape the future. See real impact.

At Quant Spark, we’re transforming how data and AI serve society. We combine the analytical discipline of strategy consulting with the pace and ownership of a scale-up. That means you’ll work directly on the problems that matter most—whether combating economic crime, modernising government services, or accelerating commercial growth for FTSE 100 companies.

Here, you’ll compress 5–10 years of traditional career progression into 2–3 years. From day one, you’ll lead end-to-end projects, access leadership directly (including the CEO), and build cross-industry expertise that usually takes a decade to gain.
We don’t just develop—we build, own, and scale solutions that shape the organisations we work with and have meaningful societal impact.

We partner with forward-thinking organisations across sectors:

• Private Equity & Financial Services: Portfolio analytics, AI-powered value creation, and risk management tools for global investment and wealth firms.
• Retail & Consumer: Pricing optimisation, inventory efficiency, and personalised engagement for major UK retailers and brands.
• Asset Management: Advanced investment platforms and automated risk management for asset managers.
• Public Sector: Trusted by multiple UK government departments for fraud analytics, predictive maintenance, and supply chain optimisation.
• SaaS & Manufacturing: Sector-spanning technology transformation for SaaS innovators and manufacturers.

As a Senior Developer, you’ll design, build, and scale robust, impactful web applications using both backend and frontend technologies. In this role, you’ll:

• Drive the architecture, design, and delivery of scalable, secure, and maintainable software solutions for commercial clients across multiple sectors.
• Guide and mentor junior developers through hands‑on leadership, code reviews, and knowledge‑sharing.
• Write, review, and own high‑quality code primarily in Python (using frameworks like Flask, FastAPI, or Django) and JavaScript/Type Script (preferably React).
• Develop and maintain RESTful APIs and modern user interfaces, ensuring an excellent user experience and technical excellence.
• Work directly with clients providing technical expertise and guidance.
• Work with cross‑functional teams to gather requirements, design solutions, and deliver features that make a meaningful impact.
• Contribute to system design and technical strategy, leveraging experience with cloud (e.g., AWS), containers (Docker/Kubernetes), and database systems (Postgre
  
  SQL, MySQL, or Mongo
  
  DB).
• Collaborate closely with Data Engineers on data pipelines and large‑scale data processing.
• Champion best practices in software engineering, TDD/unit testing, and documentation.

• You’re an experienced full‑stack engineer (4+ years), with at least 1 year in a senior or lead role, regularly mentoring others.
• You have a track record in designing and delivering enterprise‑grade web applications and APIs.
• You’re deeply knowledgeable in Python backend frameworks and modern frontend frameworks (React/Type Script), and comfortable across the full product lifecycle.
• You enjoy solving complex technical problems, delivering elegant code, and driving architectural decisions.
• You’re proactive, accountable, and collaborate well in fast‑paced, cross‑functional teams.
• You’re excited by autonomy, and the chance to shape both team standards and technical direction.

• Accelerates my growth by giving me tech ownership and autonomy from day one.
• Lets me see my work and high‑value impact within months.
• Provides direct exposure to executives, not layers of hierarchy.
• Values diversity of thought, background, and approach.

• A team of technical entrepreneurs who think differently and thrive on technical challenge.
• Colleagues who share openly, challenge constructively, and grow together.
• Clients who are ambitious enough to reimagine how data and technology transform their…