Senior Software Engineer, Payments

Lemonway; Paris; Hybrid; EUR 90,000 - 125,000; Full time

Benefits offered by this job

Office in Sentier, Paris

Hybrid 2 days WFH

Meal vouchers Swile

Alan complementary health care

Navigo/Vélib transport reimbursement

Gymlib access

Syntec RTT holidays

Job summary

Lemonway in Paris is seeking a Senior Software Engineer for the Payments Tribe to architect, implement and evolve our card payment stack and cash management platform. You will report to the Engineering Manager and collaborate with 8 engineers across 2 squads, owning features end-to-end, mentoring peers, and shaping scalable payment services in a hybrid work setup.

Join a regulated payments environment with a strong focus on reliability, security and business value, as Lemonway continues to lead

Qualifications

• 5+ years of experience in software engineering building robust, scalable applications.
• Deep architectural knowledge: DDD, Hexagonal, EDA, and CQRS.
• Strong expertise in relational databases and microservices architectures.
• Excellent communication for technical consensus across teams.
• Familiar with .NET (C#), MS SQL, RabbitMQ, Docker, and Kubernetes.
• Experience with CI/CD pipelines and Terraform IaC.
• Fluent in French and comfortable with English.
• Nice to have: AI tools in daily workflow.
• Nice to have: Payments processing in regulated environments.

Responsibilities

• Design and deliver scalable features with balanced code quality and time spent.
• Lead code and architecture reviews, enforcing best practices and decisions.
• Mentor peers to elevate engineering standards.
• Own products from specification to production issues in production.
• Deep dive into our payment ecosystem to build resilient solutions.
• Bridge technical decisions with business value to drive payment flows.
• Collaborate with software, QA and infra engineers; translate architecture to stakeholders.
• Participate in our hybrid setup with office, home and nearshore teams.
• Balance independent problem solving with guiding teammates.

Skills

5+ years experience

DDD

Hexagonal architecture

Event-Driven

CQRS

Relational databases

Microservices

Communication skills

French language

English language

AI tools

Payments domain

Tools

C#/.NET

MS SQL

RabbitMQ

Docker

Kubernetes

Terraform

CI/CD

Job description

Lemonway is a licensed payment institution at the heart of Europe’s new digital economy.

We secure payments for crowdfunding platforms, the collaborative economy, marketplaces and online retailers, with a strong commitment to fighting fraud and protecting funds.

Regulated by the ACPR and benefiting from the European passport in 29 countries, Lemonway is based in Paris and Hamburg and brings together 150 multicultural and committed Lemonheroes.

More than 400 marketplaces trust us. We manage 1.4 million user wallets and have raised €50 million from Breega, Speedinvest and Toscafund.

Profitable for the past four years and growing by 25% in 2025, Lemonway aims to remain one of Europe’s leading payment providers through healthy and sustainable growth.

About the role

We are looking for a Senior Software Engineer for the Payments Tribe, a critical part of our platform powering the payment experience across all channels. You will report to the Engineering Manager of the Tribe, and work closely with 8 engineers across 2 squads (Core banking, Payments).

You will architect, design, and drive the enhancement of our platform by specifying, implementing, testing, monitoring and troubleshooting the services provided to our customers, working across payment APIs, processing, reconciliation, and core banking systems.

This role combines technical craftsmanship, teamwork and product mindset for a Tribe that is central to both current and future projects for Lemonway. You will play a pivotal role in designing and delivering our next-generation card payment stack for acquiring and issuing, as well as our cash management platform.

Your responsibilities

Technical craftsmanship

• Design and deliver scalable, complex features that can evolve with the right trade-off between code quality and time spent
• Lead code and architecture reviews, actively enforcing and shaping the Tribe’s best practices and architectural decisions
• Drive continuous improvement: stay updated on the latest ecosystem trends, experiment with new patterns, and actively mentors peers to elevate the Tribe’s engineering standards

Domain ownership

• Take strong ownership of the products we develop, and contribute to all parts of the development cycle from specifying to solving issues that our clients are facing in production
• Deep dive into our complex payment ecosystem. Ask tough questions, challenge the status quo, and leverage your architectural expertise together with domain knowledge to build resilient solutions
• Understand the “why” behind the “what”: bridge the gap between technical implementation and business value, ensuring our payment flows directly drive Lemonway’s operational success and client satisfaction

Team player

• Collaborate closely with software, QA and infrastructure engineers to solve technical challenges, as well as product managers for feature development
• Act as a technical communicator: translate complex architectural decisions into clear, actionable insights for both technical and non-technical stakeholders
• Participate actively in our hybrid setup with people at the office, at home, and nearshore
• Strike the right balance between independent problem-solving and guiding teammates, whilst being solutions oriented in your approach

Your qualifications

• You have 5+ years of experience in software engineering, building robust and scalable applications
• You have deep architectural knowledge and proven hands-on experience with Domain-Driven Design (DDD), Hexagonal architecture, Event-Driven Architecture, and Command Query Responsibility Segregation (CQRS)
• You have strong expertise in relational databases and a proven track record of designing, building, and operating micro services-based architectures
• You possess excellent communication skills, enabling you to drive technical consensus and collaborate effectively across teams
• You are familiar with our technical stack based on modern .NET (C#), MS SQL, RabbitMQ, Docker, and Kubernetes
• You have practical experience in building CI/CD pipelines and using Terraform for Infrastructure as Code (IaC)
• You are fluent in French and you are comfortable working in English, which is a strong asset given our international environment
• (Nice to have) You actively leverage AI tools in your ways of working
• (Nice to have) Knowledge of payments processing in a regulated environment

What we offer

• Offices in Sentier, at the heart of Paris
• A hybrid way of working with 2 days of WFH/week
• Meal vouchers through Swile
• Alan complementary health care plan
• 50% Reimbursement of your monthly transportation pass Navigo/Vélib
• Access to Gymlib for a healthier lifestyle that works for you
• Holiday and RTT plan aligned with the Syntec agreement