Software Engineer III - Full Stack

An Introduction to Primer

We’re the world's first unified payment infrastructure, empowering businesses worldwide to unleash their payment potential. By choosing our platform, merchants can take control over their payment stack, create unique commerce experiences, accelerate their roadmap and increase payment success. We strive to make something complex, incredibly simple and intuitive. The world's top investors, including Accel, Balderton, Iconiq, and Tencent, have invested in Primer's vision to rebuild payments and commerce from the ground up.

Join us in shaping the future of payments and commerce.

Our engineering teams work fully remotely across Europe but we are focusing our hiring strategy on these locations: UK 🇬🇧, Hungary 🇭🇺, Romania 🇷🇴, Serbia 🇷🇸, Turkey 🇹🇷, Bosnia 🇧🇦, and Greece 🇬🇷.

Unfortunately we are unable to offer VISA sponsorships or relocation packages at this time.

Which team will you be joining?

A Primer payment is worth so much more than a regular payment!

Our Optimization team enables merchants to optimize their payments KPIs. Ultimately, we’re looking to improve payment success, increase adoption and increase expertise.

This team covers: Fallbacks, Fraud Prevention, Network Tokenization and Observability Dashboards.

Reporting to an Engineering Manager, you’ll join a team of backend, fullstack, and frontend engineers all working together alongside our Product team.

The team adopts a ‘you build it, you own it’ approach, working with infrastructure, doing their own testing and QA.

Our tech stack includes: Python, Typescript, React, AWS, Kubernetes and Terraform amongst lots of other things.

🔍 What will you be doing? 

• Improve and optimize fallback mechanisms to ensure seamless payment processing.

• Enhance reliability by implementing smart routing and failover strategies.

• Redesign data pipelines to improve monitoring, tracking, and real-time insights.

• Ensure data accuracy and integrity across payment systems.

• Build and refine an A/B testing framework to test different payment flows.

• Develop if X, then Y decision-based logic to optimize transaction success rates.

• Enable rapid iteration and data-driven improvements in the payments experience.

👀 What we’d love to see: 

• A Full-Stack Developer with a strong focus on Frontend development (JavaScript/TypeScript + React).

• Someone comfortable working across the stack, with some backend experience (Python preferred) but primarily frontend-heavy.

• Experience with testing frameworks and a good approach to writing testable, maintainable code.

• Be willing to set goals, success metrics, driving and setting up sprints and driving refinement sessions of the tickets and driving delivery side on a day to day basis.

• In-depth understanding of the entire development process (design, development and deployment)

• Highly motivated self-starter who values autonomy and getting things done

• Excellent verbal and written communication skills

• Experience working in a fast-paced environment.

🚫 You may not like it here if:

• You enjoy working in an office-setting, we are remote-first and always will be!

• You are not comfortable with shifting context and navigating ambiguity

• You don’t enjoy testing your code, we have no testers or QA’s here at Primer

Our interview process

• 30 minute call with a Talent Partner

• 45 minute interview with an Engineering Manager

• 90 minute pair programming interview

• 60 minute final stage values-alignment interview

What’s life like at Primer?

We’ve been recognised as a top global employer, #1 in FinTech for ‘flexibility’!

We’re building a culture where people can come and do their best work and enjoy it. We want our people to be proud of the impact that they have at Primer, and of the work that they are doing. You will be working with a team of people who are mission-driven, smart, and reflective, and who are invested in building exceptional products and delivering success for our merchants (and we also know how to have fun along the way).

We work remotely. We believe that building a successful, profitable company goes beyond proximity. We invest in our relationships with each other through great remote working practices and thoughtfully designed face-to-face time together. Our heads-together time comes in the form of workstations, our annual company retreat, and co-working space access worldwide.

Finally, let’s go ahead and say it. The work that we do is challenging. Startups are a challenge, building category defining products is a challenge. You should be prepared for a challenge at Primer. But, there’s a big difference between a challenge and a struggle. The key difference is that the right challenge comes with the right support structures, an acceptance that not everything always goes to plan, a collaborative environment, and a great team around you. It’s never a challenge that you will face alone.

Our benefits

🌍 We are fully remote and globally distributed; and have been since day one

💰 Competitive share options

🌴 Uncapped holiday, with 25 days minimum to be taken

🗣️ Co-working space access

📅 Workations & Company Retreat

💻 The best equipment for your role

🏠 £500 towards your home office setup

🔎 Generous learning budget

🏥 Private Medical Insurance

📈 A broad set of additional perks and benefits (depending on location)

Don’t meet every single requirement?

At Primer, we’re dedicated to building a diverse, inclusive, and authentic workplace. If you’re excited about this role but your past experience doesn’t align perfectly with every qualification in the job description, we encourage you to apply. You may be the right candidate for this or other roles. Primer is committed to the equal treatment of all current and prospective employees, regardless of background or beliefs.

Primer adopts a zero-tolerance approach to discrimination. We are committed to providing equal opportunities to all current and prospective employees regardless of age, disability, sex, sexual orientation, pregnancy and maternity, race or ethnicity, religion or belief, gender identity, or marriage and civil partnership.