Senior Software Engineer - Cards Experience EU in London

As a Senior Software Engineer on the Cards Experience EU team, you'll be a key technical contributor in building and evolving the core card spending experience within the Spend domain. You'll work alongside a team of experienced engineers across multiple European hubs, collaborating closely with staff engineers and cross‑functional partners to deliver complex, high‑impact initiatives in a fast‑moving environment.

The team is currently focused on several urgent strategic projects, and you'll play a hands‑on role in driving them forward — writing production code, shaping technical designs, and helping the team execute with quality and pace. You'll contribute to the technical direction of the platform and help navigate a highly specialised domain that includes card infrastructure, banking integrations, and complex flows of funds, balancing immediate delivery needs with long‑term platform sustainability and maintainability.

You'll bring strong technical judgement, a bias for pragmatic solutions, and a genuine interest in the reliability and scalability of systems that customers across Europe depend on every day.

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 being part in understanding what our customers pains are with our product team, design documents, coding to 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.

At Perk, we believe the best work happens when great people come together in small teams, with a shared sense of purpose. You'll join a cross‑functional squad where you have real ownership of a piece of Perk’s domains, a genuine say in what gets built, and the autonomy to make it happen. Each team decides how to contribute to Perk’s company goals. We care about impact, and we trust our people to deliver it.

At Perk, we take an IRL‑first approach to work, where our team works together in‑person 3 days a week. As such, this role requires you to be based within commuting distance of our hubs. For certain roles, we can help with relocation from anywhere in the world. English is the official language at the office.

AI is embedded in how we work and what we build. On the engineering side, it spans the whole workflow: our Notion, Jira, GitHub and Slack are AI‑connected so you get up to speed fast, and day‑to‑day it helps with specifying features, writing and reviewing code, and automated AI PR review on every pull request. When something goes wrong in production, AI surfaces context across systems quickly. We also embrace agentic coding, using AI as an active collaborator, not just a prompt‑by‑prompt co‑pilot.

We expect candidates to use AI tools in our coding interviews. The bar is understanding your code and owning what you produce. That reflects how we work every day.

Some examples of what it means to be a Senior at Perk:

• 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.
• 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.
• 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.

Desired skills and experience:

• Product Leadership: Translate complex business goals into technical roadmaps; de‑risk ambiguous projects through spikes and prototyping.
• System Architecture: Architect scalable, evolvable systems and data models that account for performance, failure isolation, and long‑term maintenance.
• Technical Standards: Define and uphold engineering excellence, including CI/CD optimizations, testing strategies, and coding standards across the stack.
• Frontend Strategy: Establish frontend architecture patterns, including state management, performance budgets, and comprehensive testing (e.g., E2E/Cypress).
• Backend Excellence: Engineer sophisticated backend solutions involving API versioning, caching strategies, and complex data migration plans.
• Operational Maturity: Lead observability and SRE practices; define SLOs, manage incident responses, and conduct blameless post‑mortems.
• Security & Risk: Oversee operational security, including secrets hygiene and dependency risk management, to ensure a hardened production environment.
• Mentorship & Influence: Level up the engineering organization through active mentorship, leading design reviews, and influencing the product roadmap with technical data.
• Cross‑Functional Impact: Coordinate multi‑team deliverables and align stakeholders to resolve technical blockers across the organization.
• AI‑Driven Development: Experience with—or a strong interest in—modern AI‑augmented workflows.

Perk is a global company with a diverse customer base, and we want to make sure the people behind our product reflect that. We’re an equal opportunity employer, which means you’re welcome at Perk regardless of how you look, where you’re from, or anything else that makes you, well, you.