Software Engineer

Aries Global; England; On-site; GBP 60,000 - 80,000; Full time

Job summary

A rapidly-scaling software group in the United Kingdom is seeking a Senior Software Engineer to design and build foundational systems for their platform. This hands-on role includes responsibilities such as developing internal tools and collaborating with cross-functional teams to drive real business impact. The ideal candidate has 4+ years of backend experience, strong coding skills in modern languages, and is excited about solving high-leverage challenges.

Qualifications

• 4+ years of experience building backend systems, AI agents, APIs, or infrastructure.
• Comfortable working in fast-paced environments with shifting priorities.
• Experience building integrations or platform services.

Responsibilities

• Design and develop internal tools, APIs, and agents for SaaS.
• Quickly turn high-level ideas into working products based on feedback.
• Build tools that support GTM agents and enable better decision-making.

Skills

Backend systems

AI agents

APIs

Infrastructure

Python

Ruby-on-Rails

TypeScript

Go

System design

Cloud infrastructure

Job description

Overview

The Role: Senior Software Engineer. As a Senior Software Engineer on the core Aries engineering team, you'll play a key role in designing and building the foundational systems that power our platform - enabling fast iteration, deep visibility, and scalable growth across our SaaS portfolio. This is a hands-on role for a technical builder who's excited to solve high-leverage challenges, prototype experimental tools, and contribute meaningfully to our engineering culture. You'll work alongside a small, senior team and collaborate closely with product, data, and AI functions.

Let's Build: If you're excited by the idea of building from 0 to 1, solving real-world problems, and shaping a world-class engineering org - we'd love to hear from you.

Responsibilities

• Build Core Infrastructure: Design and develop internal tools, APIs, and agents that integrate data, systems, and workflows across our SaaS group.
• Prototype with Purpose: Quickly turn high-level ideas into working products and iterate based on business feedback.
• Engineer Growth Systems: Build tools that support GTM agents, automate workflows, and enable better decision-making at scale.
• Collaborate Cross-Functionally: Work closely with product managers, data scientists, and AI engineers to deliver real business impact.
• Integrate & Stitch Systems: Connect 3rd-party APIs and internal services via clean interfaces and stateful pipelines.
• Champion Code Quality: Write clean, maintainable, well-tested code while mentoring others on engineering best practices.
• Help shape the culture and direction of a fast-moving, well-funded platform business.

Qualifications

• 4+ years of experience building backend systems, AI agents, APIs, or infrastructure in modern programming languages (Python, Ruby-on-Rails, TypeScript, Go, etc.).
• Comfortable working in fast-paced environments with shifting priorities and high autonomy.
• Experience building integrations, internal tools, or platform services.
• Strong product sense: you care about what you're building and how it helps the business.
• Solid understanding of system design, async workflows, and cloud infrastructure (bonus: experience with agent-based architectures or state machines).
• Enthusiastic about learning, growing, and collaborating across disciplines.

About Aries

Aries is a rapidly-scaling, next-generation software group purpose-built to scale founder-led, mission-critical SaaS companies at the heart of the $50B+ cloud ecosystem. We unify niche B2B SaaS businesses under Aries' AI and Growth Platform - unlocking visibility, velocity, and value across our portfolio. With a permanent capital base and $200M invested annually, we're building a new model for software scale focused on long-term value.