Senior Software Engineer - Sustainable Engineering

Role Overview

As a Senior Software Engineer on the Pay Sustainability Engineering team, you’ll help drive the long-term reliability, scalability, and evolution of our payments, financial and billing ecosystems.

The team operates across two complementary tracks. The first focuses on firefighting and platform support, helping engineering teams navigate critical incidents, unblock complex technical challenges, and improve coordination across the broader payment infrastructure. Rather than acting as a delivery team for operational work, you’ll provide technical leadership, platform-wide visibility, and guidance that helps teams resolve issues effectively and prevent recurring problems.

The second track focuses on medium- to large-scale sustainability initiatives across the payments domain. This includes identifying technical debt, platform limitations, architectural weaknesses, and product gaps that impact the long‑term health of the ecosystem. You’ll lead initiatives that improve the resilience, maintainability, and scalability of the platform through thoughtful refactors, system redesigns, and engineering improvements that create lasting impact.

As a senior engineer, you’ll play a key role in defining what sustainability engineering means within the Pay organization. You’ll partner closely with engineering and product teams to shape the value proposition of the function, prioritize high‑impact opportunities, and provide technical direction across complex cross‑functional initiatives.

Through strong technical leadership, systems thinking, and a focus on sustainable engineering practices, you’ll help build a healthier, more scalable payments platform that enables teams to move faster with greater confidence.

At Perk, we know that we feel most fulfilled when we can own the problem and the solution. This means taking responsibility for the entire lifecycle of a feature, from understanding our customers’ pain points with the product team, through design, coding, deployment, and measuring impact. You will see how your technical decisions move the needle for our customers daily.

We prioritize autonomy and pragmatism, giving you the space to solve complex problems without unnecessary friction. Engineering excellence here is measured by the reliability and simplicity of the systems you build to power a global platform.

• Shape the bigger picture. You won't just build features, you'll refine the what to build and why. At Perk, senior engineers are expected to go beyond the technical solution and focus on the problem itself. You'll contribute to your squad's quarterly goals and long‑term vision alongside your Product Manager and Engineering Manager.
• Architect for today and tomorrow. When a big change is needed in how our platform works, you'll be the one writing the design documents that lay the foundation. You'll become a guardian of your team's technical quality; spotting areas of investment, proactively managing technical debt, and making sure we don't let "busy work" crowd out the work that truly matters. At Perk, we believe in impact over effort: our customers see results, not the hours behind them.
  
  Your job is to make sure we're always investing our energy where it counts most.
• Lead across boundaries. Your influence won't stop at your own squad. You'll communicate complex ideas across multiple teams, proactively identify who needs to be involved, and drive alignment across the broader organisation. Whether it's coordinating a cross‑squad initiative, contributing to one of our engineering guilds, or pairing with architects on solution discovery, you'll operate comfortably beyond your immediate team.
• Raise the bar for everyone around you. Senior engineers at Perk are mentors, coaches, and bar raisers. You'll support less experienced colleagues through direct mentorship, thoughtful feedback during reviews, and by modelling what great engineering looks like in practice. You'll help Engineering Managers understand where the team needs to grow technically, and you'll use spaces like guild meetings,…