Senior Software Engineer - C# / Java

Threecolts; Bristol; Hybrid; GBP 81,000 - 99,000; Full time

Benefits offered by this job

25 days PTO

Healthcare & Pension benefits

Company-wide offsites

Regular rate reviews and bonus opportunities

Job summary

Threecolts is seeking a Software Engineer with 5–8+ years of experience to own features across Inventory Lab’s systems. You will design, build, and maintain scalable services and APIs, ensuring high performance and quality.

Key qualifications include strong proficiency in C# and Java, experience with cloud infrastructure, and the ability to handle production issues independently. The role offers a salary of £90,000 per year along with 25 days PTO and other benefits.

Qualifications

• 5–8+ years of professional software engineering experience.
• Strong proficiency in C# and Java.
• Experience building and maintaining backend services and APIs.

Responsibilities

• Take ownership of features across Inventory Lab's systems.
• Deliver clean, scalable services and maintain high quality.
• Debug production issues and contribute to architectural discussions.

Skills

C#

Java

REST APIs

SQL databases

Git

Cloud infrastructure (AWS)

Job description

Overview

Threecolts is the leading software suite for online & offline consumer brands (Amazon, Walmart, Target, Shopify, eBay, etc.). We’ve built a powerful ecosystem of software solutions to help businesses grow smarter — from revenue recovery and retail finance, to multichannel operations and pricing optimization. With over 500 employees globally and strong backing, we’re scaling fast across new markets and new partner channels. We’re an AI enabled company, with AI integrated across development through operations, empowering teams to move faster, build better, improve quality, and make more informed decisions.

We hire exceptional people from all backgrounds and give them the autonomy to move fast and the accountability to deliver, where you will wear multiple hats, take ownership of challenges, and proactively solve problems beyond your immediate scope. Change is constant, ambiguity is part of the deal, and clear, concise communication is how we stay aligned, so when in doubt, bring people in.

Key Responsibilities

• You’ll take ownership of features across Inventory Lab’s C# and Java-based systems, delivering them from initial design through to production. You’ll design and build clean, scalable services, APIs, and components that are maintainable, well-tested, and performant.
• You’ll operate independently within a defined scope, making sound technical decisions and balancing speed with long-term quality. You’ll play an active role in improving the systems you work on, debugging production issues, identifying root causes, and implementing durable fixes.
• You’ll contribute to technical discussions, help evolve architecture within your domain, and raise the bar through thoughtful code reviews. Collaboration is key: you’ll work closely with Product, QA, and DevOps to build features and improvements that deliver meaningful value to Inventory Lab customers.

What We’re Looking For

• 5–8+ years of professional software engineering experience
• Strong proficiency in C# and Java
• Experience building and maintaining backend services, APIs, and scalable application components
• Solid understanding of REST APIs, system design, and scalable application patterns
• Experience working with SQL databases and data modelling
• Familiarity with cloud infrastructure, ideally AWS
• Experience debugging production systems and resolving issues independently
• Comfortable working with Git, code reviews, and team-based development
• Ability to work across an existing codebase and improve quality without over-engineering

Compensation, Perks & Benefits

• Salary: £ 90,000 per year
• 25 days PTO
• Healthcare & Pension benefits
• Opportunity to join company-wide offsites
• Regular rate reviews and bonus opportunities
• Fully remote/hybrid working