Senior Full Stack Developer

Responsibilities

• Work closely with Product Management to understand the business needs and find appropriate technical solutions.
• Design, own and operate scalable, secure payment systems that handle financial transactions efficiently in a multi‑tenant Cloud/SaaS environment.
• Lead architecture reviews, make trade‑off decisions for scalability, security and maintainability, and coach other engineers on design and implementation.
• Design, implement and test in-store payment and payment device interactions including credit/debit, gift cards, digital wallets, and more.
• Contribute to the definition of the team roadmap.
• Lead end to end design, delivery, and reliability of our solutions.
• Define and drive platform patterns, CI/CD improvements, SLIs and SLOs, observability and testing strategy for our solutions' flows.
• Work with engineers from different teams to ensure technical excellence of the whole platform.
• Ensure that functional and non-functional requirements (performance, security) are met.
• Take part in on‑call rotation (with the worldwide distributed team) for production systems.

Qualifications

• Proven experience as a TypeScript backend engineer building and operating large-scale production systems, including designing CI/CD pipelines, integrating observability tooling, and implementing structured logging, among other platform best practices.
• Solid understanding of parallel and asynchronous programming, as well as non-blocking I/O.
• Solid grasp of distributed systems fundamentals, including consistency models, replication, and asynchronous processing, with a clear understanding of their practical trade-offs.
• Experience in developing REST APIs and knowledge of scalable architectures.
• Knowledge of document databases (MongoDB) and API interaction tools (such as Postman, or similar).
• Hands‑on experience building frontend applications using modern frameworks (e.g. React, Next.js), with the ability to deliver end‑to‑end features across the full stack — from API design to UI implementation.
• Fluent written and verbal English language skills for work in international teams.
• The aspiration to constantly improve yourself and learn new technologies and concepts.
• Good understanding of Agile methodologies and participation in sprint events.
• Ability to work in a hybrid environment.
• AI Aptitude: A genuine curiosity for using AI tools to work smarter and more effectively, paired with a drive to learn and put them into practice in your role.

Nice to Have

• Experience with MACH principles and solutions composed in MACH environments.
• Experience with industry standard API Authentication/Authorization, including OAuth, OpenID Connect, SAML 2.
• Experience integrating, implementing, and supporting at least one major PSP provider/gift card processor such as Adyen, Stripe, PayPal, Braintree, Worldpay, GlobalPay, GiveX, Clutch, Elavon, or Savvy.

Location and Working Arrangements

This role is hybrid, with three days a week spent in our London office.

Benefits

• Comprehensive health benefits for you and your dependents, including access to OpenUp for personalized mental health support.
• Learning and development opportunities including an annual learning budget, access to self‑paced learning platforms and language training, personalized coaching, mentorship, and leadership programs.
• Family Leave Plus which gives additional fully paid weeks of parental leave on top of government‑provided leave.
• Equity participation program to share in the company's success.

Equal Opportunity Statement

We proudly welcome applicants of every race, color, religion, gender identity, sexual orientation, age, and any other part of your identity that makes you who you are. As an equal opportunity employer, we believe that our strength lies in our diversity, and we invite you to be a part of our global community. For more information on our diversity, equity, inclusion and belonging practices, please visit this page.