Full Stack Software Engineer - Payments B2B

Job Description

We're looking for a full-stack engineer to join our Payments B2B team.

You'll be working on the systems that give salon owners clarity and confidence over their financial lives: reconciliation, invoicing, transaction history, pay-ins and payouts. You'll also work on the internal tooling that keeps our ops, support, and compliance teams running smoothly at scale.

You'll work across the full stack — Java and Spring Boot on the backend, React and TypeScript on the frontend — owning what you build from conception to production.

You bring the mindset of someone who has genuinely sat with a small business owner and understood what it means when their financial data doesn't add up. You care about getting that right.

Our product is built on:

• Backend: Java, Spring Boot, RabbitMQ, PostgresSQL, MS-SQL 
• Frontend: React, TypeScript, Cypress, Jest
• Infrastructure: Kubernetes, GitLab CI/CD, AWS, Datadog
• Mindset: DevOps, DDD, event-driven architecture

You will be responsible for:

• Financial transparency for partners — evolve the systems behind reconciliation, invoicing, transaction history, and payin/payout flows that salon owners rely on daily
• Internal tooling — iterate and improve the tooling that empowers our ops, support, and data compliance teams to move fast without creating risk
• Platform reliability — own your services end-to-end, from architecture through deployment, with a DevOps mindset baked in
• Experimentation — contribute to a culture that validates ideas with data before committing to them at scale

About Treatwell

Hi, we’re Treatwell. Nice to meet you.

We’re a team of 700 passionate and brilliantly talented people across Europe. We’re the industry’s smartest salon management software, all connected to Europe’s leading bookings platform, working with over 50,000 salon partners across 13 countries, processing over 8 million bookings every month. And….breathe.

But we’re not done yet. We’re on an exciting journey to digitally revolutionise the hair and beauty community.

If this excites you, we might just have the role for you.

Requirements

About you: 

• You have proven experience owning production-grade web applications end-to-end, and understand that the best technical decisions come from deeply understanding the problem — not just the code (mid/senior level)
• You own features end-to-end — from database schema to UI, without needing a handoff
• You think in systems and trade-offs, not just tickets — you spot the upstream cause, not just the downstream symptom
• You have a product mindset — you think about the person using what you build, ask why before how, and push back when something doesn't make sense
• You're data-driven — you instrument your work, measure impact, and use evidence to make decisions
• You proactively contribute, align with others, and help teams deliver outcomes together.
• You are able to make progress in evolving or complex domains while collaborating to create clarity — payments and financial data are complex domains, and you know how to navigate that without getting paralysed
• Experience in fintech, payments, or financial SaaS (B2B context a plus) (nice to have)
• Experience with AI-assisted development tools such as Claude, Cursor, or similar — and clear opinions about where they genuinely add value (nice to have)
• Exposure to event-driven architectures in production at scale (nice to have)
• You can communicate fluently in English
• You are based in any city within Spain or Italy, with a valid right to work

NOTE: If you don’t meet every requirement but believe you’d thrive in this role, we’d still love to hear from you.

Benefits

We’ll treat you with:

• 28 days' holiday, plus local bank holidays
• Monthly £/€40 Treatwell vouchers so you can treat yourself too
• Mental health support through our partnership with Open-Up
• 100% remote position with flexible working within Italy or Spain. Candidates outside of these locations will not be considered for the role
• Market-specific benefits that will be discussed during the interview process

Equal Ops

Treatwell is an ‘Open to All’ employer and warmly welcomes everybody to the team. We are committed to making reasonable adjustments to the recruitment process as required. Please add any adjustment requests to your application.