
Tech4 Ltd
Senior Python Developer
Job Description
Salary: £80,000 - 110,000 per year
Requirements:- Deep experience building scalable, secure, cloud-based systems
- Proven ability to work across both legacy and greenfield codebases
- Strong system design fundamentals across scalability, performance, and distributed systems, including API design (REST, GraphQL)
- Hands-on experience with observability tooling (Datadog, Grafana, or similar) and a data-informed approach to system health and reliability
- Solid SQL and data management skills, with an appreciation for AI-enabled, data-driven systems
- Familiarity with CI/CD, containerisation (GitHub Actions, GitLab CI, Docker), and DevSecOps practices in modern AI development environments
- A pragmatic approach to testing, knowing what to cover, what to skip, and how to use AI to improve efficiency
- Experience mentoring engineers and supporting the adoption of modern tools and AI-native workflows
- Strong communication skills and the ability to articulate technical decisions and trade-offs clearly
- Help the team move faster by adopting AI-native workflows and the shift to an agentic development lifecycle, without compromising the architectural qualities that make our platform reliable, scalable, and maintainable over the long term
- Define guardrails, review practices, and validation gates that hold AI-generated code to our standards for security, reliability, and cost-efficiency (FinOps)
- Design, build, and operate software across our platform, applying the same rigour to AI-augmented work as to anything else you ship
- Embed deeply with Product and Design from the earliest stages of discovery, using rapid prototyping and iteration to compress the gap between idea and validated solution
- Act as feature lead on a rotating basis, taking accountability for the development and delivery of a feature from shaping through to production
- Shape platform architecture with an architectural lens, contributing to long-term decisions about how AI tooling, LLM integrations, and human-in-the-loop controls evolve across the stack
- Continuously identify and exploit opportunities to improve performance, reliability, and user experience, using observability and analysis to find signals in noisy systems
- Navigate confidently across legacy and greenfield contexts, applying AI tooling pragmatically to modernise where it matters most
- Set the engineering standard, demonstrating through your own work what excellent looks like when much of the code is AI-generated
- Grow the teams capability and confidence with AI-native practices, coaching more junior engineers to think critically about model outputs, prompt design, and the boundaries of automation
- Define and evolve best practices for code quality, testing, documentation, and delivery in a world where much of the first draft is AI-generated
- Evolve CI/CD pipelines to incorporate agentic workflows, automated testing, AI-assisted code review, and intelligent deployment gates
- AI
- API
- CI/CD
- Cloud
- Datadog
- DevSecOps
- Docker
- GitHub
- GitLab
- Grafana
- GraphQL
- LLM
- Python
- REST
- SQL
- Security
- Azure
- GCP
- React
More:
We are a fast-growing and highly successful international organisation seeking a Senior Python Developer to help evolve and extend our platform while guiding technical direction and supporting team development. This is a predominantly hands-on role, with around 20–30% of time focused on technical leadership, architecture, mentoring, and shaping how the team works. We offer excellent training and career development opportunities, excellent benefits, and the role is based in London with a hybrid working arrangement.
last updated 38 week of 2026
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About Tech4 Ltd

Tech4 Ltd
St Paul's
IT
Skills & Technologies
Inferred from job description
Salary Insight
£95,000
This role
£75,000
UK median
This salary is 27% above the UK median for Senior roles (£75,000/yr).
Based on 2024–2025 UK technology sector benchmarks