Software Development Engineer

• Develop software products that meet defined functional and non-functional requirements, proactively clarifying ambiguities when specifications are incomplete or evolving.
• Design or contribute to pragmatic technical solutions aligned with the innovation objectives of future products, balancing speed, quality, and sustainability.
• Assess and compare off-the-shelf solutions with in-house development options to identify the most effective and efficient approach.
• Apply industry standards and best practices across software development, integration, and delivery.
• Actively participate in, and when required lead, the investigation and resolution of problems and incidents through to final resolution.
• Ensure the quality, performance, and sustainable evolution of applications in both the short and long term.
• Drive continuous improvement to ensure software remains robust, maintainable, and adaptable over time.

What makes you a great fit

The role requires comfort with ambiguity and the ability to adapt quickly to changing needs, requirements, and technologies. Continuous learning, adaptability, and ongoing improvement are core to how the team operates and how success in this role is defined.

• Ruby & Ruby on Rails - at least 5 years of hands-on experience with Ruby on Rails, including ActiveRecord, RSpec or Minitest, and background job processing (Sidekiq or similar).
• Front-end development - solid experience with JavaScript and at least one modern front-end framework.
• Databases - strong SQL skills (PostgreSQL preferred) and experience with ORMs such as ActiveRecord.
• REST APIs - experience designing and consuming REST APIs, webhooks, JSON and OpenAPI/Swagger documentation.
• Git & CI/CD - comfortable with git workflows, CI/CD pipelines and doing code reviews.
• Linux - at ease with the Linux command line in daily work.
• Software delivery - you understand the full development lifecycle, from turning business needs into technical solutions through testing to release and change management.

Strong Plus

• Vue.js - hands-on experience with Vue.js (ideally Vue 3).
• Elixir / Phoenix - experience with Elixir and Phoenix, or a real interest in learning them. Part of our backend is written in Elixir.
• AI-assisted development - interest in working with AI coding tools as part of your daily workflow. We use Claude Code across the team.

Nice to Have

• Messaging - knowledge of RabbitMQ or other message brokers and event-driven architectures.
• Docker - building and running containerized applications.
• Security - understanding of OAuth 2.0, OpenID Connect, JWT and token-based authentication, encryption and HTTPS.
• Monitoring & observability - experience with Kibana (ELK stack) and APM tools.
• AWS - familiarity with services like ECS, EC2 or API Gateway.
• Other API formats - JSON:API, SOAP.

Let’s shape the future of finance - together

At Isabel, we believe that real innovation happens when people and ideas connect

That’s why we’re building more than technology, we’re building an ecosystem.

One where every voice counts, and where your work can truly make a difference.

We’re looking for curious minds and collaborative builders. People who believe success means growing together, learning from each other, and challenging the status quo., Ruby on Rails · Elixir · Phoenix · Vue.js · PostgreSQL · RabbitMQ · Docker · Kibana / APM · Claude Code

Why join us

At Isabel, we offer more than a job, we offer a place to grow, contribute, and thrive.

• A human-sized Belgian company (250 people) where your ideas and impact matter
• 50% hybrid work, flexible hours, and autonomy to manage your time
• Coaching, training, and tailored development paths for every career stage
• A flat, collaborative structure with real ownership and cross-functional work
• Competitive rewards: Flex Income Plan, annual bonus, insurance, meal vouchers

• A strong engagement culture and inclusive mindset

• Easy mobility options: our MOBI strategy supports flexible, low-footprint commuting, whether by bike, public transport, or electric car
• Professional gatherings that encourage collaboration and networking, as well as fun and purposeful activities led by our BeFun team
• A certified Top Employer with 30 years of tech leadership and ambition

Ready to join us?

Your voice, your vision, and your impact all have a place here.

Let’s shape smarter solutions and a stronger digital economy. Together.