Full Stack Engineer

Harnham - Data and Analytics Recruitment; Greater London; Hybrid; GBP 80,000 - 120,000; Full time

Benefits offered by this job

Competitive base salary

Flexible working options across London

Autonomy from day one

Exposure to complex data systems

Small high-impact team

Clear progression as team scales

Job summary

Harnham - Data and Analytics Recruitment is seeking a Senior Full Stack Engineer to join a hybrid London-based team. You will build AI agents, develop prototypes, and modernise legacy systems, delivering measurable results across the data platforms.

You’ll work with Python, TypeScript, and SQL in a fast-paced environment, collaborating with senior engineering leadership to ship features weekly and maintain high-quality code, APIs, and documentation.

Qualifications

• Strong commercial experience delivering software in fast-paced environments.
• Hands-on development across Python, TypeScript, and SQL.
• Comfortable working with modern AI tooling and agent-based development workflows.
• Experience working with data systems, including schema design, data quality, or lineage.
• Ability to understand and work across unfamiliar codebases effectively.
• Clear communication skills, including writing high-quality pull requests and presenting work.
• A proactive, self-directed approach with a focus on delivering outcomes quickly.

Responsibilities

• Build internal AI agents and tools that improve productivity and unlock value from group data
• Develop prototypes that validate ideas quickly and can be demonstrated on a weekly basis
• Modernise legacy systems using AI-assisted analysis and development approaches
• Wrap existing systems with clean, scalable APIs to enable wider consumption
• Generate documentation, tests, and migration tooling to support platform evolution
• Contribute to shared data and entity platform development across the organisation
• Continuously improve code quality, leaving systems clearer and more maintainable

Skills

Python

TypeScript

SQL

AI tooling

Agent-based development

Data systems

Codebase comprehension

Communication

Tools

API design

AI tooling platforms

Job description

Senior Full stack Engineer

£80,000 - £120,000

Hybrid - London (3x days per week)

The Company

They are a data focused organisation bringing together multiple specialist businesses, each with its own technology stack and domain expertise. Their central technical team is responsible for unifying systems, modernising legacy platforms, and building AI-enabled capabilities that can be leveraged across the group. The environment is highly collaborative, delivery-focused, and driven by experimentation and measurable outcomes.

The Role

You will sit within a small, high-performing technical core, working closely with senior engineering leadership to deliver rapid, tangible results.

• Build internal AI agents and tools that improve productivity and unlock value from group data
• Develop prototypes that validate ideas quickly and can be demonstrated on a weekly basis
• Modernise legacy systems using AI-assisted analysis and development approaches
• Wrap existing systems with clean, scalable APIs to enable wider consumption
• Generate documentation, tests, and migration tooling to support platform evolution
• Contribute to shared data and entity platform development across the organisation
• Continuously improve code quality, leaving systems clearer and more maintainable

Your Skills and Experience

• Strong commercial experience delivering software in fast-paced environments
• Hands-on development capability across Python, TypeScript, and SQL
• Comfortable working with modern AI tooling and agent-based development workflows
• Experience working with data systems, including schema design, data quality, or lineage
• Ability to understand and work across unfamiliar codebases effectively
• Clear communication skills, including writing high-quality pull requests and presenting work
• A proactive, self-directed approach with a focus on delivering outcomes quickly

What They Offer

• Competitive base salary
• Flexible working options across London and remote environments
• High levels of autonomy and ownership from day one
• Exposure to complex data systems and AI-driven engineering challenges
• Opportunity to work in a small, high-impact team with visible output
• Clear progression as the team and platform scale