Senior Full Stack Engineer

Crooton; Peterborough; Hybrid; GBP 55,000 - 65,000; Full time

Job summary

A leading AI recruitment firm in Peterborough is seeking a Senior Full Stack Engineer to join their small, senior team. This position involves working on greenfield AI-driven projects, requiring expertise in React and Python. The role offers a hybrid working model with a salary range of £55,000 to £65,000, along with performance-related bonuses. Ideal candidates are those who thrive on building modern user interfaces, can develop async APIs, and are passionate about creating impactful technology solutions.

Benefits

Performance-related bonus

Hybrid working model

No legacy technical debt

Qualifications

• Deep experience with modern React, especially with Hooks and Composition.
• Comfortable building and maintaining async APIs using FastAPI and Pydantic.
• Strong commitment to code testing and quality.

Responsibilities

• Build and ship full-stack features for AI visualisations and workflows.
• Design complex React components for a high-performance UI.
• Refine LLM prompting logic for candidate scoring improvements.
• Extend FastAPI services focusing on strong typing and async performance.

Skills

Modern React

Python (FastAPI)

AI Integration

Async APIs

Testing (Pytest, Vitest, Cypress)

Tools

Google Vertex AI

Postgres

Docker

Job description

Senior Full Stack Engineer | AI-Recruitment SaaS (React \& Python)

Location: Peterborough / Hybrid

Salary: £55,000 – £65,000 + Bonus

Tech: React (TS), Python (FastAPI), Google Vertex AI, Postgres, GCP

Build the Future of AI-Driven Recruitment

Are you a Senior Engineer who thrives on "greenfield" projects? Do you want to work on a platform where AI isn't just a buzzword, but the core engine of the product?

Join Crooton to help us build our AI-powered recruitment intelligence platform. We are solving the biggest headache in high-volume hiring: processing thousands of applications with speed, fairness, and intelligence, as well as saving time and money.

This isn't a legacy rescue mission. You’ll be joining a small, senior team to write modern, well-structured code and shape the technical roadmap of a platform that’s already making an impact.

The Tech Stack

You’ll be working with:

• Frontend: React, TypeScript, Vite, Tailwind CSS, Zustand.
• Backend: Python 3.10+ (FastAPI), Postgres, Redis.
• AI/Infrastructure: Google Vertex AI, GCP (Cloud Run), Docker, CI/CD.

What You’ll Be Doing

• End-to-End Ownership: Building and shipping full-stack features, from AI analysis visualisations (Chart.js) to advanced workflows.
• High-Performance UI: Designing complex React components and ensuring our "Command Centre" remains lightning-fast under heavy data loads (AG Grid).
• AI Integration: Refining LLM prompting logic and CV parsing to improve candidate scoring and bias reduction.
• Scaling Architecture: Extending our FastAPI services with a focus on strong typing, validation, and async performance.

Who You Are

We are looking for a "Product Engineer"—someone who cares as much about the user experience as they do about the underlying architecture.

• Frontend Expert: You have deep experience with modern React (Hooks, Composition) and building data-heavy interfaces.
• Python Pro: You are comfortable building and maintaining async APIs (FastAPI/Pydantic).
• Testing Advocate: You believe in the "Testing Pyramid" (Pytest, Vitest, Cypress).
• Problem Solver: You enjoy solving ambiguous, real-world problems and want meaningful ownership rather than just "clearing tickets."

Why Join crooton?

• No Legacy Drag: Work on a modern stack with no inherited technical debt.
• AI-First Culture: We use AI to accelerate our own development and iteration.
• Senior Collaboration: Work closely with our Leadership Teamin an environment that values clean architecture and good engineering judgment.
• Real Impact: As part of a small team, you will see your work used immediately by organisations hiring at scale.
• The Package: £55k–£65k DOE + performance-related bonus and a hybrid working model in Peterborough.

Ready to apply?

If you’re a clear communicator who cares about code quality and security, we want to hear from you.

Apply today with your CV and (optional) GitHub profile.