Senior Software Engineer (Fullstack)

Jack & Jill/External ATS; Greater London; On-site; GBP 100,000 - 105,000; Full time

Job summary

A high-growth e-commerce platform in London is seeking a Senior Software Engineer to own and deliver core product features. You will write maintainable Ruby on Rails and JavaScript code while ensuring system reliability. Ideal candidates have expert-level experience in engineering and strong product intuition. This position offers clear career progression and a high-performance culture emphasizing deep work and team excellence.

Qualifications

• Expert-level experience with Ruby on Rails and modern JavaScript.
• Strong product intuition and ability to break down complex requirements.
• Pragmatic mindset utilizing AI and automation for improvements.

Responsibilities

• Own and ship core product features from design to delivery.
• Drive engineering excellence with maintainable code.
• Enhance internal developer experience through tooling and automation.

Skills

Ruby on Rails

JavaScript

SQL

AWS

Continuous improvement mindset

Job description

Overview

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack.

Role

Senior Software Engineer (Fullstack)

Salary: £100-105k

Location: London, UK

Company

Company: Judge.me - High-growth e-commerce trust platform powering hundreds of thousands of merchants globally.

Job Description

Join Judge.me to solve real-world commerce problems for hundreds of thousands of global merchants. You will own core product features end-to-end, writing clean Ruby on Rails and JavaScript code while navigating ambiguity to drive high-impact outcomes. This role offers clear career progression into Staff or Leadership tracks within a results-driven, engineering-first culture.

Why this role is remarkable

• Significant scale and impact, building trust-based commerce tools used by over 200,000 active merchants across the globe.
• Exceptional career mobility with defined growth paths into Staff Engineer or Engineering Management roles as the team scales.
• High-performance culture that prioritizes deep work, short feedback loops, and sustainable excellence over long hours and bureaucracy.

What you will do

• Own and ship core product features end-to-end, from initial design through to delivery on a global scale.
• Drive engineering excellence by writing maintainable code across Rails, JavaScript, SQL, and AWS while improving system reliability.
• Identify and remove friction in the internal developer experience by enhancing tooling, automation, and observability workflows.

The ideal candidate

• Expert-level experience with Ruby on Rails and modern JavaScript, with a track record of delivering high-quality production systems.
• Strong product intuition and the ability to decompose complex, ambiguous requirements into clear, executable technical steps.
• Pragmatic mindset focused on continuous improvement, utilizing AI and automation to accelerate development velocity and team output.

Who are Jack & Jill?

Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.

Next steps

1. Visit our website.
2. Click 'Talk to Jack'.
3. Talk to Jack so he can understand your experience and ambitions.
4. Jack will make sure Jill (the AI agent working for the company) considers you for this role.
5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.
6. If not, Jack will find you excellent alternatives. All for free.

We never post fake jobs

This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it.

Closing

Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.