Backend Engineer - London Onsite

LJ Recruitment; London; On-site; GBP 60,000 - 80,000; Full time

Job summary

A high-growth London startup seeks a Backend Engineer to build core systems that handle complex workloads. The ideal candidate has over 3 years of backend experience, preferably in a startup setting, and excels in system design. This office-based role in Soho offers a competitive salary, unlimited holiday, and a vibrant, high-energy culture. Join a team dedicated to transforming enterprise software and redefining performance standards.

Benefits

Competitive salary

EMI share options

Private health cover

Unlimited holiday

Monthly wellbeing budget

Qualifications

• 3+ years backend engineering experience, ideally with distributed systems emphasis.
• Experience in high-velocity startups transitioning from MVPs to solid systems.
• Ability to take problems end-to-end with strong system design skills.

Responsibilities

• Build core systems for handling large-scale LLM workloads.
• Own architecture components from job orchestration to APIs.
• Enhance system reliability and quality across infrastructure.

Skills

Backend engineering experience

Strong system design skills

Exposure to distributed systems

Pragmatic and resourceful mindset

Tools

Kotlin

TypeScript

Terraform

Azure/AWS/GCP

Job description

Overview

Backend Engineer - Scale Systems with Real Impact

Tired of tinkering at the edges? Want to actually shape the backbone of a platform that's transforming how the world's biggest enterprises run their tech? This is one of those rare roles where you get in early, build the foundations, and watch your work scale across global businesses.

We're working with a high-growth London startup on a mission to reinvent enterprise software. Their AI-driven platform is already saving household-name customers millions in IT costs, shaving months off ERP project timelines, and making sense of the mess that legacy systems leave behind. SAP is just the beginning - they're building a whole new category of Enterprise System Intelligence.

The Role

• Build core systems capable of handling tens of millions of lines of code and large-scale LLM workloads.
• Own big pieces of the architecture - from job orchestration to APIs, infra, and developer tooling.
• Make product teams fly by building reliable, well-designed infrastructure that scales without slowing anyone down.
• Tame complex LLM infrastructure (real-time usage, flaky providers, token routing - the lot).
• Raise the quality bar across the board: observability, auth, reliability, and more.

This isn't a role for passengers. It's for engineers who love ambiguity, thrive under pressure, and see infrastructure as a multiplier.

What We're Looking For

• 3+ years backend engineering experience (ideally with some distributed systems / infra focus).
• Exposure to high-velocity startups and the shift from scrappy MVPs to rock-solid systems.
• Strong system design skills - taking problems end-to-end, not just handing off parts.
• Bonus if you've wrangled LLM infrastructure at scale.
• Pragmatic, resourceful, and happy to operate autonomously in lean teams.
• Excited to work onsite in Soho, London with a team that's building something exceptional.

Tech Snapshot (don\'t worry if you don\'t know it all): Kotlin, TypeScript, Terraform, Azure/AWS/GCP, Temporal, Postgres, graph databases, OpenTelemetry, Grafana, containerised dev environments, CI/CD pipelines.

Perks & Culture

Competitive salary + EMI share options
Breakfast and dinner on tap, plus snacks that raise the bar
Regular socials + full-team offsites twice a year
Private health cover (dental + optical included)
Monthly wellbeing budget
️ Unlimited holiday (take what you need, no counting)
High-trust, high-energy culture - serious about impact, never too serious about ourselves

Location

Location: Soho, London (office-based by default)