Senior Python Backend Engineer, London (£85-110,000 p.a.)

Alexander Charles; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Hybrid work model

London office

Job summary

Alexander Charles is seeking a Senior Backend Engineer to design and build a scalable Python backend on AWS, with well‑designed APIs and distributed systems. You will own backend architecture and deliver robust, well‑tested services aligning with governance‑led product thinking.

You will work hands‑on with Terraform, Kubernetes and EKS, and leverage AI coding agents within automated loops to drive the SDLC while maintaining security and reliability at scale.

Qualifications

• 5+ years shipping production backend software as a senior engineer.
• Strong Python backend development experience in scalable, production systems (distributed systems & APIs).
• Solid AWS experience (5+ years) with Terraform, Kubernetes and EKS.
• Deep understanding of API design, data modelling, performance, reliability & observability.
• Hands-on experience with Claude Code or similar AI coding agents in automated SDLC loops.
• Comfort owning backend architecture decisions.
• Experience with LLM-based systems or AI/ML product development.
• Thrives in early-stage, fast-changing environments and collaborative work.
• Excellent collaboration with product & engineering teams.
• Master’s degree in STEM.
• Nice to have: governance, compliance, security, or regulated industries.
• Nice to have: startup/pre-Series A experience.

Responsibilities

• Architect and build scalable, secure Python backend on AWS and APIs.
• Own backend services end-to-end: data modelling, performance, reliability, observability, security.
• Collaborate with cloud infra using Terraform, Kubernetes and EKS to deploy services.
• Leverage AI-assisted development workflows (Claude Code) in SDLC workflows.
• Set and uphold backend engineering standards: CI/CD, testing & release practices.
• Partner with frontend engineers to design clean API contracts.
• Contribute to technical direction and roadmap discussions.
• Use AI tools in planning, coding, testing and review to accelerate delivery.
• Seek continual improvements in processes and tooling.

Skills

Python backend

AWS

API design

Data modelling

Terraform

Kubernetes / EKS

AI coding agents (Claude Code)

Observability

Security / compliance

Backend architecture ownership

Education

Master's degree in STEM

Tools

Terraform

Kubernetes

EKS

Job description

The purpose of this role as Senior Backend Engineer is to design and build the scalable, secure Python backend and services at the heart of our AI governance platform. This is a hands‑on, high‑impact individual‑contributor role at the centre of a fast‑moving start‑up: you’ll own backend architecture and delivery, make pragmatic technical decisions, and translate complex, governance‑led product thinking into robust, well‑tested services that the business customers who rely on us can trust.

You will report to the Director of Technology and work in close, day‑to‑day collaboration with the wider engineering team and Lead Developer — underpinning the rapid launch and development of our AI‑native service. You’ll be joining early enough to shape not just the platform, but how engineering happens.

The Role

The Senior Backend Engineer role sits at the intersection of backend engineering, cloud infrastructure and AI‑augmented delivery. You will take backend architecture from concept through to production, focusing on a scalable Python backend on AWS, well‑designed APIs and distributed systems, and harness‑based AI‑assisted development workflows.

Key Responsibilities

• Architect and build a scalable, secure Python backend on AWS, including distributed systems, asynchronous architectures and well‑designed APIs.
• Own backend services end‑to‑end — data modelling, performance, reliability, observability and security.
• Work hands‑on with cloud infrastructure using Terraform, Kubernetes and EKS to deploy and operate your services.
• Use harness‑based, AI‑assisted development workflows — running Claude Code or similar coding agents in automated loops to handle the majority (80%+) of the SDLC, from planning through implementation, testing, and review.
• Set and uphold backend engineering standards: code quality, CI/CD, testing, and release practices.
• Partner with front‑end engineers and the UI/UX Lead to design clean, well‑documented API contracts.
• Contribute to technical direction and roadmap discussions with the Director of Technology and founders.
• Use AI tools throughout your own workflow — for planning, coding, testing and review — to accelerate delivery without compromising quality.
• Continuously look for better ways of working — in your process, your tools and your output.

Profile

• 5+ years’ experience in shipping production backend software as a senior engineer.
• Strong Python backend development experience (5+ years) in scalable, production systems, including distributed systems, asynchronous architectures and APIs.
• Solid hands‑on AWS experience (5+ years), with strong DevOps exposure to Terraform, Kubernetes and EKS.
• Deep understanding of API design, data modelling, performance, reliability and observability.
• Hands‑on experience developing software using Claude Code or similar AI coding agents, running them in automated loops and using them to drive 80%+ of the SDLC (planning, coding, testing, review).
• Comfortable owning backend architecture decisions.
• Professional experience with familiarity with LLM‑based systems or AI/ML product development.
• Comfort operating in an early‑stage, fast‑changing environment, where priorities shift and ambiguity is normal — someone who leans into that rather than waiting for certainty.
• Excellent collaboration skills, working as an equal partner to product and other engineers.
• Master’s degree in a STEM field (Computer Science, Software Engineering, or related discipline).
• Nice to have: experience in governance, compliance, security, or regulated industries.
• Nice to have: prior experience at an early‑stage startup, ideally pre‑Series A.

The Problem You’ll Help Solve

In this role you will help address challenges such as:

• ensuring complex technologies remain transparent and accountable
• helping organisations adopt AI safely and responsibly
• building governance systems that support innovation rather than slow it down.

What You’ll Help Build

The initial build of all new product capabilities including:

• designing and building the scalable backend and infrastructure underpinning corporate memory and governance frameworks for advanced technologies
• building and continuously improving technology platforms
• working with partners to co‑create new tools and capabilities
• translating complex technical or regulatory concepts into practical, shippable engineering solutions
• contributing to the evolution of products, research, or partnerships.

What Success Looks Like

Success in this role will be defined not just by tasks completed, but by the impact created.

Examples may include:

• A reliable, scalable and secure backend that supports rapid product iteration
• Well‑designed APIs and services that other engineers can build on with confidence
• Highest levels of security and compliance including SOC2, Cyber Essentials Plus and ISO, enabling a capability that sails through due diligence
• Clear linkage between backend delivery and commercial growth

We look for people who take ownership of outcomes and continuously seek better ways of working.

Practical Details

Location: London, UK (Hybrid — 3 days/week in office)

Team: within the Engineering organisation

Role Type: Permanent, full‑time role

Right to work: Applicants must already hold the right to work in the UK. We are unable to sponsor visas for this role

Reports to: Director of Technology

Works closely with: the wider Engineering team, and Lead Developer