Senior Software Engineer - Billing Automation - 12 Month FTC

What We’re All About

Any company can tell you about how they are a multi award winning, market leading business — and yes, we are both of those things in the world of IoT connectivity. But we’re more than that. Our mission is to make IoT management a breeze for any device, anywhere.

With over 10 million IoT subscriptions active in 165 countries and direct partnerships with 50 mobile networks, we connect customers to more than 750 networks worldwide, delivering unmatched value across the IoT connectivity chain.

Innovation is in our DNA, and we have an insatiable hunger to ‘wow’. While we may not always get it right, our drive to collaborate, innovate, and achieve top-notch customer satisfaction never wavers.

The Role — Pulsar Squad

The Pulsar Squad owns a core part of our commercial platform: billing automation and the billing run — a mission-critical, high-volume pipeline that turns large-scale usage data into timely, accurate invoices for customers worldwide. It’s a technically rich and genuinely complex domain: event-driven workflows, large data volumes, financial correctness, and operational reliability at scale.

We’re looking for a Senior Software Engineer — a hands-on, predominantly backend engineer who is at home in a mature PHP / Symfony platform, comfortable with RabbitMQ-based asynchronous processing, and confident working deep in PostgreSQL. You’ll take ownership of meaningful pieces of the billing platform, from understanding the business problem through to running your code in production.

Much of the platform has grown over many years, so a big part of the job is working effectively with legacy code: understanding it, making it safer to change, and improving it incrementally without disrupting our customers. You’ll also contribute to the squad’s gradual modernisation, in which capabilities are extracted step by step (strangler-fig approach) into focused domain services, some of them in TypeScript.

You’ll report to an Engineering Manager and work day to day with the squad’s Delivery Manager, other senior engineers and stakeholders from the wider business who depend on billing being right.

This role is based in the UK with the squad based in Poland that you will work with virtually. This is a 12-month Fixed Term Contract.

Key Responsibilities

• Build, optimise and maintain backend services and features in PHP 8.x / Symfony that are correct, well tested and easy to operate
• Work confidently in a mature, legacy codebase — build understanding of existing behaviour, add tests around it, and refactor incrementally so it becomes safer and simpler to change
• Build and evolve event-driven, asynchronous workflows on RabbitMQ, with careful attention to idempotency, retries, ordering, error handling and recoverability
• Build, optimise and maintain PostgreSQL schemas and queries for data-intensive billing processes — indexing, query tuning and diagnosing performance issues on large data sets
• Own your work end to end — from refinement and technical design through implementation, thorough automated testing (unit, integration and end-to-end where it matters), release and production support — working self-sufficiently and knowing when to pull others in
• Contribute to the modernisation of the platform under the technical direction set by the Engineering Lead, helping to define seams, extract capabilities safely and keep billing correct throughout
• Uphold engineering standards for code quality, testing, observability and operational readiness across both legacy and new components
• Help keep our services healthy in production — contribute to SLIs/SLOs and dashboards (Grafana), take part in investigating and resolving incidents, and follow through on improvements
• Use and improve our CI/CD pipelines (GitLab and AWS CodeBuild) to keep releases small, frequent and safe
• Collaborate closely with Product and business stakeholders to clarify requirements in a complex domain, explain technical trade-offs in plain language, and flag risks early
• Give thoughtful code reviews and share knowledge, supporting less experienced engineers in the squad
• Use AI-assisted engineering tools responsibly (IDE agents, CLI tooling, reviews), staying accountable for the correctness of what ships

Key Experience & Skills

Required

• Solid commercial experience as a backend engineer (typically 5+ years), delivering and running business-critical systems in production
• Deep, production-proven expertise in PHP 8.x and Symfony — modern, strongly typed PHP, clean architecture and good testing practice
• Hands-on experience with RabbitMQ (or a comparable message broker) and event-driven / asynchronous processing
• Strong command of PostgreSQL — data modelling, query design, indexing and performance tuning on large volumes of data
• Proven ability to work with legacy systems — understanding unfamiliar code, safely changing it, and improving it incrementally rather than rewriting
• Experience building data-intensive, business-critical services where correctness, idempotency and recoverability matter
• Comfort working in a complex business domain — able to dig into domain rules, ask the right questions and model them well in code
• Self-sufficiency — able to take loosely defined problems, break them down and drive them to completion with minimal supervision
• Strong communication and stakeholder skills — can explain trade-offs clearly and honestly to engineers, Product and non-technical stakeholders
• Experience working with CI/CD pipelines (GitLab, AWS CodeBuild or equivalent) and automated testing

Preferred

• Familiarity with AWS-based platforms (e.g. ECS, S3, Parameter Store, CodeBuild, Managed RabbitMQ, IaC i.e. Terraform)
• Exposure to TypeScript / Node.js (ideally NestJS), or interest in working across both PHP and TypeScript services
• Experience contributing to the modernisation or decomposition of a monolith — e.g. strangler-fig, anti-corruption layers, incremental cut-overs
• Background in billing, financial, or metering/rating domains
• Experience with distributed/sharded PostgreSQL setups (e.g. Citus)
• Practical experience with observability — metrics, tracing, logs; Grafana or similar
• Experience with PHP / Symfony monorepos and shared library patterns
• Sensible, hands-on use of AI-assisted development tools (e.g. Cursor, Claude Code, GitHub Copilot) with a thoughtful view on where they help and where they don’t

What Will Make You Shine at Wireless Logic

• Takes ownership — treats the billing platform as their own and cares about outcomes, not just tickets
• Is calm and pragmatic with legacy code — improves things step by step and keeps the lights on while the platform evolves
• Creates clarity — turns ambiguous domain problems into simple, well-structured solutions
• Cares about correctness — thinks about edge cases, failure modes and data integrity before they become incidents
• Communicates early and openly — shares progress, risks and trade-offs with the team and stakeholders
• Manages technical debt with intent — makes informed, defensible calls about when to refactor
• Partners with Product — understands the business outcome behind the work and shapes the solution accordingly
• Lifts the team — shares knowledge through reviews, pairing and documentation
• Keeps learning — including thoughtful adoption of new tooling and AI-assisted workflows

Why Come Work with Us?

• The chance to join a creative, entrepreneurial company where bold ideas are celebrated
• Full training, ongoing support, and the tools to help you thrive and grow in your role
• A company with heart — we genuinely care about our people and make sure everyone feels valued, respected, and part of the team

Overview of Interview Process

• Tele Interview — Meet the people team
• Online Technical Task
• Behavioural Interview — Meet your hiring manager
• Technical Interview — Meet the Engineering Lead and a peer engineer (expect a discussion on working with legacy code, messaging and PostgreSQL)
• System Design Interview — Meet more peers (expect a discussion on designing reliable, event-driven billing workflows)

How We Work

We’ve adopted a hybrid working approach to give flexibility on where and how we work. This role is based in Poland to support squad collocation; you’ll find out more about what this means for the role during the recruitment process.