Senior Python Developer

Tech4 Ltd; Greater London; Hybrid; GBP 80,000 - 110,000; Full time

Benefits offered by this job

Hybrid work arrangement

Job summary

Tech4 Ltd is seeking a Senior Python Developer to evolve our platform and guide technical direction from London, in a hybrid role. You will contribute hands-on software engineering 20-30% in leadership, architecture, mentoring, and shaping how the team works.

You will collaborate with Product and Design from discovery through rapid prototyping, applying AI-native workflows to keep the stack reliable, scalable, and maintainable, while mentoring others and developing AI-enabled features.

Qualifications

• Deep experience building scalable, secure, cloud-based systems.
• Proven ability to work across legacy and greenfield codebases.
• Strong system design fundamentals across scalability, performance and distributed systems.
• Hands-on observability tooling experience (Datadog, Grafana).
• Solid SQL and data management skills for AI-enabled systems.
• Familiarity with CI/CD, containerisation (Docker), and DevSecOps in AI environments.
• Experience mentoring engineers and driving AI-native workflows.
• Excellent communication to articulate trade-offs.

Responsibilities

• Move the team toward AI-native workflows while preserving reliability and scalability.
• Define guardrails, reviews, and gates for AI-generated code.
• Design, build, and operate software across the platform with AI augmentation.
• Embed with Product and Design from discovery through prototyping.
• Act as feature lead, accountable for delivery from shaping to production.
• Shape platform architecture for AI tooling and LLM integrations.
• Improve performance, reliability, and user experience via observability.
• Navigate legacy and greenfield contexts, modernising where it matters.
• Set engineering standards demonstrating AI-generated code quality.
• Grow team capability with AI-native practices and prompt design.

Skills

Cloud architecture

System design

Mentoring/leadership

Communication skills

DevSecOps

Tools

Datadog

Grafana

Docker

GitHub Actions

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

Responsibilities:

• 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

Technologies:

• 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.