> Markdown version of [/jobs/ext/2140396-senior-full-stack-engineer](https://www.wearedevelopers.com/jobs/ext/2140396-senior-full-stack-engineer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Senior Full Stack Engineer

- **Company:** Quantspark
- **Location:** London, UK
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Clean Code Principles, JavaScript (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, Data Analysis, Software as a Service, Cloud Computing, Software Quality, Code Review, Continuous Integration, Django Web Framework, Python (Programming Language), Software Tools, TypeScript, Web Applications, ReactJS, Flask (Web Framework), Large Language Models, Backend, Fastapi, Front End Software Development, Restful APIs
- **Published:** August 20, 2026
- **Apply:** https://www.apply4u.co.uk/jobs/senior-full-stack-engineer/42930229

## About the Role

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. The Role You'll design, build, and scale web applications across backend and frontend, owning projects from ideation through to production - architecture, CI/CD, cloud infrastructure, monitoring, the lot. We're a small team that punches well above its weight. Client feedback is outstanding, and every engineer here has a visible impact., with prompting patterns, tool use, and concepts like RAG and embeddings. Awareness of safety and privacy concerns when using AI tools (secrets, PII, licensing). Ability to integrate AI into your workflow without compromising code quality. What We're Looking For 5+ years' experience as a full-stack engineer. Strong track record delivering enterprise-grade web applications and APIs. Confident across Python backend frameworks and modern frontend (React/TypeScript). Comfortable owning the full product lifecycle. Proactive, accountable, and effective in small, fast-moving teams. Clear communicator across technical and non-technical audiences. Keen to broaden into a generalist whilst deepening your core strengths - not just staying in one lane. What We Offer Tech ownership and autonomy from day one. High-impact work - you'll see real results within months, not years. Room to innovate, not just maintain. A small, collaborative team that owns problems end to end and learns fast. Clients

## Description

Day to day, you'll: Architect and deliver scalable, secure software for commercial clients across multiple sectors. Assess technical trade-offs and guide design decisions across projects. Write, review, and own high-quality code - primarily Python (Flask, FastAPI, or Django) and JavaScript/TypeScript (React preferred). Build and maintain RESTful APIs and modern frontends. Work directly with clients - communicating clearly, understanding the why behind what you're building. Feed into new client proposals and help improve internal engineering processes. Mentor junior developers through code reviews, pairing, and knowledge-sharing. Use AI coding agents to accelerate delivery whilst maintaining correctness and security. AI Engineering (Required) Hands-on experience with AI coding agents in day-to-day work - prompting, iterating, reviewing generated code, validating outputs. Working understanding of LLM fundamentals and limitations (hallucinations, context windows, evaluation). Familiarity


## Related Videos

- [Watch Tests Go Brrrr! : Getting Started with Cypress in ReactJS](https://www.wearedevelopers.com/videos/282-watch-tests-go-brrrr-getting-started-with-cypress-in-reactjs)
- [Developing the Backend with Stefan Lingler, CTO at Shpock](https://www.wearedevelopers.com/videos/100360-developing-the-backend-with-stefan-lingler-cto-at-shpock)
- [Intro to FastAPI](https://www.wearedevelopers.com/videos/462-intro-to-fastapi)
- [Inside Bitpanda's Tech Stack: Scaling a European Fintech Leader - Markus Dorner](https://www.wearedevelopers.com/videos/1979-inside-bitpanda-s-tech-stack-scaling-a-european-fintech-leader-markus-dorner)
- [Meet Your New BFF: Backend to Frontend without the Duct Tape](https://www.wearedevelopers.com/videos/682-meet-your-new-bff-backend-to-frontend-without-the-duct-tape)
- [Nest.js - TypeScript in the backend can also be clean](https://www.wearedevelopers.com/videos/1033-nest-js-typescript-in-the-backend-can-also-be-clean)

## Related Articles

- [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers)
- [Why Upskilling And Reskilling is Important For Developers](https://www.wearedevelopers.com/magazine/428-why-upskilling-and-reskilling-is-important-for-developers)
- [Fullstack Developer Salary UK](https://www.wearedevelopers.com/magazine/251-fullstack-developer-salary-uk)
- [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated)
- [7 Most Popular Web Developer Jobs in Europe](https://www.wearedevelopers.com/magazine/163-7-most-popular-web-developer-jobs-in-europe)
- [Navigating the AI Shift](https://www.wearedevelopers.com/magazine/629-navigating-the-ai-shift)