Senior Software Engineer

ob description

Resale is growing rapidly, with the global second-hand clothing market expected to grow from around $288bn today to nearly $400bn by 2030. Yet the work of listing, managing, and selling individual items is still manual, expensive, and inefficient. Listing Monster is building the professional resale platform for people who buy and sell goods at scale — from full-time resellers to charities and ambitious side businesses.

We’re a small, experienced team building practical software that solves real commercial problems using AI. We care about thoughtful engineering, clean solutions, and real progress — not hype.

We’re growing and looking for a Senior Product Engineer to help us scale both our platform and the way we deliver functionality to customers.

This is a hands-on engineering role for someone who has built and shipped production software at meaningful scale before, and knows what good looks like.

Who This Role Is For

This role is ideal for someone who has already spent several years building real products used by real customers.

You are someone who has:

• A strong academic background in Computer Science, maths or a related discipline
• Has worked on and scaled production systems with meaningful usage
• Has helped teams ship faster and understands that done doesn’t end with the releasing of code
• Thinks deeply about product impact, not just technical implementation
• Enjoys improving systems, processes, and engineering culture
• Can take ownership of ambiguous problems and move them forward
• Has experience in architecting distributed systems
• Strong understanding of databases

We’re looking for someone who can help us create an amazing product by making better technical decisions, improve delivery, and raise the level of engineering across the company.

What You’ll Actually Be Doing

You’ll be:

• Helping us architect the overall platform
• Building and shipping important product features
• Helping scale our platform as usage grows
• Improving how quickly and reliably we get functionality to customers
• Working across the product, backend, frontend, AI, and operations parts of the system
• Identifying bottlenecks in our product and engineering processes
• Improving reliability, observability, performance, and maintainability
• Supporting and mentoring more junior developers
• Helping turn customer and business needs into well-designed technical solutions

This is not a role where you’ll just be handed tickets.

We’ll expect you to understand the product, challenge assumptions, spot risks early, and help us build the right things in the right way.

What We’re Looking ForEssential

• Strong experience building and maintaining Software as a Service
• Excellent programming fundamentals
• Comfortable working with UX and Product Management
• Comfortable working across a modern web application stack
• Good judgement around architecture, trade-offs, and technical debt
• Experience shipping customer-facing product features
• Clear communication and strong ownership
• Ability to work independently in a small team
• A pragmatic approach to engineering — thoughtful, but not over-engineered

Strong signals

• You’ve helped scale a product, platform, or engineering team before
• You’ve worked in a startup or scale-up environment
• You’ve a strong understanding of observability and shipping code
• You’ve made meaningful contributions to architecture or technical direction
• You’ve mentored junior engineers
• You care about product outcomes, not just code quality

What Success Looks Like

In this role, success means helping us move faster without becoming fragile.

You’ll help us:

• Refine our product offering
• Ship useful functionality to customers more frequently
• Keep the platform reliable as usage grows
• Make better technical decisions earlier
• Reduce unnecessary complexity
• Improve engineering standards and habits
• Build systems that are easier to change over time

We want someone who has seen what good looks like at scale and can help us bring the right lessons into our stage of growth.

Salary & Location

Salary: £100k-£130k depending on experience

Location: Onsite in our London office at least 3 days per week, SE1 9PG

Benefits: Private healthcare, 25 days holiday, pension

What It’s Like to Work Here

Small team, low ego

Direct communication

Pragmatic engineering decisions

Real customers using what we build

We’re a startup, which means things evolve — but we’re not chaotic. We plan carefully and build deliberately.

You’ll have a meaningful say in how the platform develops, how the engineering team works, and how we turn ideas into reliable customer-facing functionality.

There’s a lot to build, and we’re looking for someone who can help us do it well.