Senior Freelance Scala Software Engineer - Team Payment

swan.io; Bordeaux; Sur place; EUR 50 000 - 70 000; Plein temps

Résumé du poste

Swan, a leading embedded banking specialist in Europe, seeks a Senior Freelance Software Engineer to join their tech team for a specific project. The role involves designing bank APIs, enhancing system performance, and ensuring compliance in a regulated environment. Suitable candidates will have extensive experience in back-end development and a strong grasp of JVM languages.

Qualifications

• 4-5 years as a Software Developer.
• Mastery of back-end issues.
• Good knowledge of a JVM language (Kotlin, Scala, or Java).

Responsabilités

• Technically responsible for one or more projects.
• Improve the performance of systems with growing loads.
• Ensure respect for architecture rules and automated tests.

Connaissances

Back-end systems

Performance improvements

Observability

Database queries

SQL performance improvements

Functional programming

CI/CD

English

Outils

Scala

PostgreSQL

Kafka

GraphQL

AWS

Description du poste

About

Swan is Europe’s embedded banking specialist. We empower software companies to embed banking features like accounts, cards, and payments directly into their products, under their own brand. Swan processes over €1.5 billion in monthly transactions for more than 150 companies—like Pennylane, Indy, Agicap, Libeo, and Lucca. Founded in 2019, the company has received growth capital from leading investors such as Lakestar, Accel, Creandum, Bpifrance, and Eight Roads. Swan is a principal member of Mastercard and a licensed financial institution, regulated by the French banking authority (ACPR).

Our mission

Banking belongs in business software

Many software companies already serve small businesses incredibly well: helping them send invoices, run payroll, manage inventory, and more. They’re on a mission to become the central hub for managing every aspect of business life.

But when it comes to financial workflows, there’s still a gap. Too many critical tasks like managing cash flow, tracking payments, or reconciling accounts happen outside the software, across spreadsheets, email threads, banking portals.

It’s a missed opportunity. Business software shouldn’t just record financial activity — it should run it.

To learn more about us: About Swan ; Our story.

Job description

Swan is looking for a Senior Freelance Software Engineer to join its tech team of 70+ people for a specific project over a few months.

The Engineering team is by far the largest at Swan. This team includes Software developers, who build payments and end-customer applications, as well as Infrastructure, DevOps, QA, and Security.

We build with intent, focusing on solving real problems that matter. In a regulated environment, compliance, security, and resilience are at our core. We value ownership, open collaboration, and a shared vocabulary to keep complexity manageable. Simplicity is key, clean, maintainable code wins over clever tricks. We ship fast, learn continuously, and always strive for excellence.

Your mission

• You will be technically responsible for one or more projects.
• You will have the opportunity to solve problems in one of the most demanding IT domains with a reactive architecture.
• You will design with the product team the bank by API.
• You will improve the performance of a system with a rapidly growing load.
• You will ensure the respect of the architecture rules and of the automated tests.

Our technical environment

• Scala; FPTS; Typelevel; PostgreSQL; Kafka; GraphQL; K8S; AWS

Preferred experience

You’re a great match if:

• Experience: From 4-5 years as a Software Developer with a strong grasp of back-end systems.
• Mastery of common back-end issues (performance improvements, observability, database queries (SQL) and SQL performance improvements)
• Good knowledge of a JVM language (Kotlin, Scala, or Java)
• Hands-on experience with automated testing & CI/CD
• Bonus: Familiarity with GraphQL, Kafka, and microservices architecture
• Passionate about functional programming & open source
• Always up to date with tech trends (meetups, blogs, side projects)
• Fluent in English
• Our ideal teammate: Empathetic, skilled, frank. We love to challenge each other, and we leave our egos at the door.

It’s okay if you don’t tick all the boxes — don’t let imposter syndrome prevent you from applying!

Swan is committed to providing a caring work environment for all employees, regardless of age, sex, disability, sexual orientation, race, religion, or belief.

When it comes to recruitment, we’re interested in your work experience, skills, and overall personality. Because diversity makes the workplace stronger and is necessary for Swan’s success, we are intensifying efforts to incorporate concrete actions to help us improve in this area.

About Swan

Our values:

Swan’s core values guide our actions daily. Individually, they may seem obvious, but together, they form a unique culture.

Simplicity: Leonardo Da Vinci said: “simplicity is the ultimate sophistication.” If something's convoluted or confusing, we work extra hard to break it down. Making complex things simple is what we do.

Long Term: We always play the long game, whether it's to support our partners in their growth journey, or make tangible commitments to climate action.

Excellence: We are a team of experts who consistently go all out to create pixel-perfect banking services and exceed our partners' expectations—whatever it takes.

Be Human: We believe in the power of kindness and the importance of acting with integrity. But embracing our humanity extends beyond interpersonal interactions, it means caring about greater issues that affect our planet.

You can find out more about our culture.

Recruitment process

• A 30-min video call with our Talent Acquisition Manager, to get to know you, understand your career expectations, and answer your questions.
• A live coding interview with two Software Engineers.
• A hiring manager interview with an Engineering Manager.
• An interview with our Engineering Director.