Staff Software Engineer

You'll join a high-performing engineering team building our modern payments platform, currently powering corporate payments with plans to expand across all lines of business. You'll work on an event-driven, microservices architecture in Kubernetes, using Terraform, Kafka, and CI/CD to enable true continuous delivery.

You'll embrace AI-assisted engineering to set the standard for how modern software is built here.These systems run at high volume and demand exceptionally low latency and 99.99% uptime. Engineering quality here isn't a nice-to-have, it's the bar. Every design decision is made with scale, reliability, and performance in mind from day one.

As a Staff engineer, you'll take on the hardest technical problems: the ones that cross team boundaries, require deep thought, and have long-term implications. You'll set technical direction, shape architecture across the platform, and multiply the impact of every engineer you work with. Your decisions will ripple across multiple teams and services, and your work will directly shape WEX's ability to process payments reliably and securely at scale for years to come.

Who This Role Is For

This role is for engineers already operating at a Staff level: setting technical direction, shaping architecture across teams, and multiplying the engineers around them.

• Is drawn to ambiguous, high-impact problems and can bring clarity to them

• Thinks in systems, not just services, and can hold the whole architecture in their head

• Is eager to lead initiatives that span multiple platforms where needed

• Leads through influence rather than authority, earning trust through strong technical judgement

• Writes code that others learn from, and makes the engineers around them better

• Knows when to go deep technically and when to step back and see the bigger picture

• Has strong opinions loosely held, and changes their mind when the evidence says so

• Set technical direction across multiple teams and services within the Funding platform

• Lead architecture for significant initiatives, from initial design through implementation and rollout

• Identify the critical technical problems that will matter in 6 to 18 months, and drive the work to address them

• Drive platform-wide improvements in reliability, performance, scalability, and developer experience

• Make and document the technical decisions that shape how we build

• Ship production-quality C#/.NET code on the highest-leverage problems

• Design and build the systems that set the pattern for the rest of the platform

• Prototype and de-risk new approaches before they become team-wide commitments

• Use AI-assisted development tools to accelerate your own work and help others adopt them effectively

• Mentor senior and mid-level engineers through pairing, design review, and the example you set

• Raise the quality bar through code review, technical writing, and tech talks

• Build consensus across teams on technical approach, trade-offs, and priorities

• Drive engineering practices that help everyone do their best work

• Partner with Engineering Managers and Product to shape roadmap and technical strategy

• Communicate technical concepts clearly, tailoring the depth to the audience

• Represent the team in cross-functional and cross-team technical discussions

• Navigate trade-offs between short-term delivery and long-term platform health

• You're already operating at a Staff level, or doing the work of one in your current role

• You're exceptionally curious. You dig into how things work, chase down the "why," and can't help wanting to understand the system below the one you're building

• You have a deep love and understanding of system design and architectural patterns. You know the patterns, when to reach for them, and just as importantly, when not to

• You write exceptional C#/.NET code. Deep experience is required, not just exposure

• You've designed and operated distributed systems at scale in production

• You understand event-driven architectures deeply, including patterns, trade-offs, and failure modes

• You've led technical initiatives that required influence across teams, not just within one

• You take ownership of outcomes, not just output, and hold yourself to a high standard

• A track record that demonstrates Staff-level impact. Typically around 8+ years of experience, though the right person matters more than the tenure

• Deep expertise in .NET/C#. You can reason about performance, memory, async patterns, and the runtime

• Proven track record of technical leadership on complex, multi-team initiatives

• Strong experience with cloud-native systems (Kubernetes, containerisation, infrastructure as code)

• Hands-on experience with event streaming, distributed systems, and data-intensive applications

• Experience driving engineering practices such as testing strategy, observability, CI/CD, and incident response

• Experience with modern frontend technologies (Angular, TypeScript) is a plus

• Financial services or payments experience preferred but not required

You'll work with (and should have deep experience in most of):

• .NET/C# and TypeScript

• Angular

• AWS

• PostgreSQL

• Kubernetes, Terraform, Terragrunt, containerisation

• Event streaming with Kafka

• CI/CD pipelines and infrastructure as code

• AI-assisted developer tools

...and more. We're not short on interesting tech to work with.

• Work on systems that process real payments at scale. Your architectural decisions matter

• A team that values quality, ownership, and continuous improvement

• The scope to set technical direction and shape how we build across multiple teams

• Autonomy to solve problems your way, with support and backing when you need it

• An inclusive environment where your ideas are heard and your influence is valued