Software Engineer

About the role

This role structures cross-functional workflows to ship AdTech and promotions features for a global marketplace. The engineer owns the execution of backend system design and delivery for large-scale initiatives that directly impact marketplace performance. Clear communication aligns stakeholders and converts their feedback into shipped functionality that meets business goals. The position requires converting ambiguous requirements into well-defined technical solutions with measurable outcomes. You will bridge product intent and technical implementation through rigorous prioritization and execution discipline. The work involves high-stakes systems where reliability, performance, and scalability are non-negotiable. You will be expected to explain technical decisions in plain words to partners with varying technical backgrounds. Strong engineers distinguish themselves by the clarity of their reasoning and the impact of their shipped work.

Key facts

What you'll do

Design and implement complex backend problems using Golang to power critical marketplace workflows and high-volume transaction paths.

Operate scalable backend services while maintaining strict reliability targets that support global marketplace operations around the clock.

Lead large, cross-team initiatives from initial problem framing through stakeholder alignment to on-time delivery and measurable outcomes.

Gather, process, and act on partner and user feedback to drive prioritized backend improvements and data-informed product decisions.

Maintain shared objectives and transparent decisions with product, design, and operations stakeholders to ensure alignment across teams.

Apply AI-assisted engineering workflows using tools such as Codex, Claude, and agent-based development approaches to accelerate development tasks and code quality.

Model and access high-throughput marketplace data using NoSQL data platforms such as Cassandra and MongoDB to support flexible schemas and scale.

Write and maintain tests that validate system behavior under load and edge cases to ensure robustness of marketplace features.

Refactor legacy components to improve performance, maintainability, and scalability without disrupting existing production workflows.

Collaborate with site reliability engineers to define and monitor service level objectives for backend services and APIs.

Break down ambiguous requirements into technical tasks and estimate effort while communicating trade-offs to stakeholders clearly.

Champion best practices in code review, documentation, and knowledge sharing to elevate the overall quality of engineering output.

Optimize database schemas, queries, and caching strategies to handle large datasets and high request rates efficiently.

Participate in on-call rotations to respond to production incidents and contribute to post-incident reviews for continuous improvement.

Mentor junior engineers by providing constructive feedback on code, design decisions, and problem-solving approaches within the team.

Requirements

The posting states a bachelor's degree requirement that must be met for this role.

Backend engineering experience is required to own and drive complex projects independently from conception to delivery.

Strong preference is given to Golang for backend service implementation and integration within marketplace systems.

Ownership of complex, cross-team work in ambiguous environments is demonstrated through past delivery and clear results.

Stakeholder management, planning, and delivery skills are used to coordinate priorities, timelines, and dependencies across functions.

Communication and alignment-building skills keep partners informed and ensure decisions are transparent and well-documented.

Extensive experience with AI-assisted development, including tools such as Codex, Claude, and agentic workflows, is required for this position.

Experience with NoSQL databases such as Cassandra, MongoDB, or similar technologies is a plus for handling high-scale data needs.

The ability to translate business requirements into technical specifications is essential for successful project execution.

A proven track record of delivering high-availability systems that meet strict reliability and performance standards is required.

Experience working in fast-paced, high-growth environments where priorities can change rapidly is expected.

Comfort with debugging production issues and performing root cause analysis is necessary to maintain system stability.

Willingness to collaborate closely with data, product, and design teams to ensure cohesive user and partner experiences.

Nice to have

Only items that are explicitly preferred in SOURCE are included here.

Practical notes

The role is based in London and requires compliance with the listed degree requirement.

Typical interview steps

Hiring for engineering roles usually starts with a recruiter screen, followed by one or two technical rounds. Candidates often solve a coding problem, discuss past projects, and answer system design questions. Some loops include a take-home task. Final rounds typically cover team fit and give candidates a chance to ask questions. Interviewers look for how you break down an unfamiliar problem, not just whether you reach the answer. Practicing a few problems aloud and reviewing your own past projects are the best preparation.

Good to know

Backend engineering roles focus on services, APIs, and data models that power digital marketplaces.

Golang is commonly used for high-throughput services where performance and maintainability matter.

AI-assisted workflows integrate tools like Codex and Claude into coding, testing, and review practices.

NoSQL databases such as Cassandra and MongoDB suit flexible schemas and large-scale reads.

Cross-functional initiative ownership requires clear documentation and stakeholder communication.

Roles in AdTech and promotions involve fast-paced, high-availability systems and strict delivery timelines.

Career growth

Engineering careers usually progress from individual contributor to senior, staff, and principal levels. Some engineers move into management and lead teams of five to twenty people. Others stay on the technical track. Growth follows demonstrated impact, not tenure alone. A typical engineering ladder has clear levels with defined expectations for scope, quality, and mentorship. Moving up usually requires owning outcomes end to end rather than completing assigned tickets.