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Senior Software Engineer, Backend (Merchant Data Platform EU)

Affirm

Remote · PolandFull Time

Senior Software Engineer, Backend (Merchant Data Platform EU) at Affirm is a full time role based in Remote · Poland (remote). It was published on 11 March 2026 and was open at last check.

Senior Software Engineer, Backend (Merchant Data Platform EU) at Affirm — key details
RoleSenior Software Engineer, Backend (Merchant Data Platform EU)
CompanyAffirm
LocationRemote · Poland (remote)
Employment typeFull Time
Published11 March 2026
StatusOpen at last check

Affirm is reinventing credit to make it more honest and friendly, giving consumers the flexibility to buy now and pay later without any hidden fees or compounding interest.

The Merchant Data Platform is a backend, foundational service at Affirm. We are responsible for merchant data and identity across all merchant touchpoints. Our checkout-critical platform serves millions of requests per day, supports the onboarding of merchants across all onboarding touchpoints, and maintains strict availability and latency SLAs given the criticality of the service. Further, the team maintains sophisticated pipelines that enrich our datasets for the purposes of merchant identification, risk analysis, and fraud detection.

We’re looking for a Senior Software Engineer to join our fully remote team based in Europe.

What You'll Do

  • You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery.
  • You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs.
  • You will proactively identify project, process, technology or business issues, advocate for them, and lead in solving them.
  • You will drive detailed project definition, design, cross-functional alignment, estimation, in addition to task break-down, delivery, monitoring, and maintenance.
  • You will support the operations and availability of your team’s artifacts by creating and monitoring metrics, escalating when needed, and supporting “keep the lights on” & on-call efforts.
  • You will contribute to a sense of community on your team by engaging in growth and development activities such as participation in the interview process.
  • You will mentor engineers on the team to help improve their designs, code quality, and testing.
  • You will own the availability, reliability, and performance of your team’s systems.

What We Look For

  • You have 4+ years of experience as a software engineer with leadership responsibilities and experience mentoring junior engineers.
  • You have experience designing, developing and launching backend systems at scale and are proficient in one of Python or Kotlin
  • You have a track record of developing highly available distributed systems using technologies like AWS, MySQL and Kubernetes.
  • You are expert at synthesizing complex business products, and technical requirements to consistently produce high quality system designs and software.
  • You are comfortable navigating a large code base, debugging others' code, and providing feedback to other engineers through code reviews.
  • You have experience defining a technical plan for the delivery of a significant feature or system component with an elegant, simple and extensible design. You write high quality code that is easily understood and used by others.
  • You are proficient at making significant changes in a large code base, and have developed a suite of tools and practices that enable you and your team to do so safely.
  • Your experience demonstrates that you take ownership of your growth, proactively seeking feedback from your team, your manager, and your stakeholders.
  • You have strong verbal and written communication skills that support effective collaboration with our global engineering team.

Compensation & Benefits

Base Pay Grade - N

Equity Grade - 4

Employees new to Affirm typically come in at the start of the pay range. Affirm focuses on providing a simple and transparent pay structure which is based on a variety of factors, including location, experience and job-related skills.

Base pay is part of a total compensation package that may include monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidized medical coverage, dental and vision for you and your dependents). In addition, the employees may be eligible for equity rewards offered by Affirm Holdings, Inc. (parent company).

POL base pay range per year: 308,000 zł - 428,000 zł

Additional benefits include:

  • Flexible Spending Wallets for tech, food and lifestyle
  • Away Days - wellness days to take off work and recharge
  • Learning & Development programs
  • Parental benefits
  • Employee Resource & Community Groups

This role is eligible for creative tax benefits, subject to applicable law and company policy

Location - Remote Poland

The majority of our roles can be located anywhere in Poland.

**This job description is not a contractual document, and is not intended to have binding force.**

#LI-Remote

Affirm is proud to be a remote-first company! The majority of our roles are remote and you can work almost anywhere within the country of employment. Affirmers in proximal roles have the flexibility to work remotely, but will occasionally be required to work out of their assigned Affirm office. A limited number of roles remain office-based due to the nature of their job responsibilities.

We’re extremely proud to offer competitive benefits that are anchored to our core value of people come first. Some key highlights of our benefits package include:

  • Health care coverage - Affirm covers all premiums for all levels of coverage for you and your dependents
  • Flexible Spending Wallets - generous stipends for spending on Technology, Food, various Lifestyle needs, and family forming expenses
  • Time off - competitive vacation and holiday schedules allowing you to take time off to rest and recharge
  • ESPP - An employee stock purchase plan enabling you to buy shares of Affirm at a discount

We believe It’s On Us to provide an inclusive interview experience for all, including people with disabilities. We are happy to provide reasonable accommodations to candidates in need of individualized support during the hiring process.

[For U.S. positions that could be performed in Los Angeles or San Francisco] Pursuant to the San Francisco Fair Chance Ordinance and Los Angeles Fair Chance Initiative for Hiring Ordinance, Affirm will consider for employment qualified applicants with arrest and conviction records.

By clicking "Submit Application," you acknowledge that you have read Affirm's Global Candidate Privacy Notice and hereby freely and unambiguously give informed consent to the collection, processing, use, and storage of your personal information as described therein.

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Create your free OnJob profile to apply — we'll take you to Affirm's application after sign-up. · Posted 11 Mar 2026.

Senior Software Engineer, Backend (Merchant Data Platform EU) at Affirm — questions answered

What does the Senior Software Engineer, Backend (Merchant Data Platform EU) role at Affirm pay?

Affirm does not publish a salary on this Senior Software Engineer, Backend (Merchant Data Platform EU) listing, so OnJob shows no figure for it rather than an estimate. For what this role pays across the market, the OnJob salary guides aggregate the live listings that do disclose pay.

Is the Senior Software Engineer, Backend (Merchant Data Platform EU) role at Affirm remote?

Yes — Affirm advertises this Senior Software Engineer, Backend (Merchant Data Platform EU) role as remote, tied to Remote · Poland, and it is listed as full time work. Remote terms come from the employer's own posting, so confirm the expected working hours, timezone and any on-site days with Affirm before you apply.

Is the Senior Software Engineer, Backend (Merchant Data Platform EU) role at Affirm still open?

The Senior Software Engineer, Backend (Merchant Data Platform EU) posting at Affirm was open at OnJob's last check of the employer's careers page, having been published on 11 March 2026. OnJob re-checks source listings on each build and marks a role closed once it disappears, but listings can close without notice, so the employer's own page is the final word.

How do you apply for the Senior Software Engineer, Backend (Merchant Data Platform EU) role at Affirm?

Apply to the Senior Software Engineer, Backend (Merchant Data Platform EU) at Affirm role through OnJob with a free profile: OnJob scores your fit against the listing, shows the skills lowering that score, and submits an ATS-ready profile to Affirm's own application page. Creating a profile is free and needs no card.

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