Sign inGet app

Jobs › Warsaw › Listing

Staff Software Engineer, Backend (Card)

Affirm · Remote Poland

RemoteEnglish

About the role

From the employer’s listing · Affirm · posted 27 August 2026

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most.

We are reinventing credit cards entirely. We are working directly with card issuers to change how credit is used throughout the world, creating new types of cards that work for both their everyday lives and large purchases with extremely straightforward, flexible terms. You will be the lead engineer for our EU teams. You will be responsible for architecture across cards and relationships with our EU counterparts. You'll work across stacks and across the company, working both in just-in-time transaction processing that has to take place in milliseconds, along with our ledgering and reconciliation systems in post-transaction processing. This is some of the more difficult, exciting, experimental engineering work in Affirm. Join us and our team in Spain and Poland to help us revolutionize payments!

What You'll Do

  • You will be responsible for setting technical strategy for your team on a year-long time scale, and help your team tie it together with critical, business-impacting projects.
  • You will be the lead software engineer for all cards in the EU.
  • You will collaborate across teams in the product development lifecycle by collaborating with product management, design & analytics to ensure technical sustainability, risks and trade-offs are well understood and managed.
  • You will act as a force-multiplier for your team through your definition and advocacy of technical solutions and operational processes.
  • You take ownership of your team’s operations and availability by ensuring you have the right monitoring, triage rotations, playbooks, policies, testing and alerting in place to support “keep the lights on” & on-call efforts.
  • You will foster a culture of quality and ownership on your team by setting code review and design standards for your team, and advocating for them beyond your team through your writing and tech talks.
  • You will help develop talent on your team by providing feedback and guidance, and leading by example.

What We Look For

  • You have a total of 8+ years of experience as a software engineer.
  • You are proficient in designing, developing and launching backend systems at scale technologies like Python, Kotlin, AWS, MySQL, and Kubernetes
  • You are proficient in developing front end applications.
  • You have experience delivering major features, system components or deprecating existing functionality in a system through the definition of a technical and execution plan. You write high quality code that is easily understood and used by others.
  • You thrive in ambiguity, and are comfortable moving from low level language idioms all the way to the architecture of large systems to understa

Skills mentioned

Engineering (Europe)

See your match score for every role

BabZituna scores every job against your profile on six real dimensions and shows you WHY it scored that way, audited for fairness (read the public bias audit).

Get the app → ✓ 100% free for job seekers
How one job scored Example
Skills96Experience90Location84Work style74Job type61SalaryNo data

Example figures, not a real candidate. Each dimension is scored out of 100 from your own profile, and one we cannot measure says so rather than guessing.