Senior Full stack Developer

Looking for a senior engineering role where you can influence technology decisions, modernize a large-scale SaaS platform, and work on meaningful technical challenges?

Join Sympa and help shape the future of our product, platform architecture, and engineering practices in one of the Nordics’ leading HR tech companies.

Location: Espoo or Lahti, Finland (hybrid) - We regularly meet in person for planning days, hackathons, and other team events. Day-to-day work can be done either remotely or from our offices in Espoo or Lahti.

Type: Full-time, permanent
Starting date: August 2026

Over the last 20 years, Sympa has helped some of the largest companies in the Nordics put people at the centre of their strategy. Today, we support close to 1,000 customers and continue to invest heavily in our engineering organization while actively expanding our development teams.

Our engineering teams are located in Finland and Poland, and as part of our continued growth, we are now looking for a Senior Full stack Developer to join our highly skilled international engineering organization of close to 70 professionals.

We are currently undergoing a major modernization of our platform architecture and engineering practices. This includes moving toward domain-driven architecture, API-first development, event-driven integrations, modern data platforms, and increased use of open-source technologies alongside Azure-native services.

At the same time, we are investing heavily in AI-assisted software development. We see AI not simply as a coding assistant, but as a fundamental shift in how software is designed, built, validated, and maintained. Our engineers actively explore new tools and practices, including coding agents, specification-driven development, AI-assisted testing, and automation.

We believe software engineers are increasingly expected to take ownership of architecture, quality, validation, and business outcomes—and we aim to be at the forefront of that evolution.

If you enjoy solving complex technical problems, improving engineering practices, and exploring how AI can genuinely improve software development, this role could be an excellent fit.

What you will do

As a Senior Full stack Developer, you will play a key role in designing, implementing, and evolving both backend and frontend capabilities across our platform, with particular emphasis on scalable backend systems, integrations, APIs, and platform evolution.

You will work closely with lead developers, architects, product teams, and other engineers to modernize our platform while ensuring reliability and scalability for a large existing customer base.

Your responsibilities include:

• Designing and implementing scalable backend services and modern frontend applications

• Contributing to architectural decisions and long-term technical direction

• Building and evolving APIs, integrations, and event-driven solutions

• Working with modern cloud-native and open-source technologies

• Using AI-assisted development tools effectively in daily engineering work

• Reviewing and validating human- and AI-generated code, designs, and implementation plans

• Improving quality through testing, automation, observability, and CI/CD practices

• Troubleshooting and resolving complex technical and production issues

• Participating in technical planning and agile development activities

• Taking ownership of technical quality, maintainability, and long-term platform evolution

• Mentoring other developers and helping raise technical standards across teams

• Collaborating with product and design teams to deliver high-quality user experiences

• Contributing to the continuous improvement of engineering practices, tooling, and development processes

What do we offer?

Sympa combines the agility of a growth company with the stability of an established SaaS business. Engineers here have real ownership, influence over technical decisions, and the opportunity to shape how our platform and engineering practices evolve.

You will work on meaningful technical challenges related to:

• Large-scale SaaS modernization

• AI-assisted engineering practices

• Modern integration and platform architecture

• Cloud-native technologies

• Developer productivity, platform quality, and scalable ways of working

Furthermore, you will get:

• A highly skilled and collaborative engineering organization

• Opportunities to influence architecture and technical direction

• International environment with low hierarchy and high ownership

• Lunch and cultural benefits

• Support for continuous learning and professional growth

What do we value in our candidates?

We are looking for an experienced full stack engineer with strong backend expertise. You are comfortable working with complex systems and making architectural decisions, but also pragmatic enough to balance speed, quality, maintainability, and business needs in everyday development work. You enjoy improving existing solutions, collaborating across teams, and helping other developers grow while driving technical progress forward.

The following skills and experience are needed to succeed:

• Strong software development experience (around 8+ years)

• Solid expertise in backend development with C#/.NET

• Experience with modern frontend technologies such as React and Angular

• Strong understanding of APIs, integrations, distributed systems, and microservice/event-driven architectures

• Experience designing scalable and maintainable systems and data models

• Strong understanding of SQL, NoSQL, and modern data technologies

• Hands-on experience with Microsoft Azure, open-source, and cloud-native development

• Experience with CI/CD pipelines, automated testing, and modern engineering practices

• Strong sense of ownership and accountability for technical solutions, quality, and outcomes

• Strong problem-solving and collaboration skills

• Ability and willingness to mentor or support other developers

• Degree in Computer Science, Engineering, or equivalent practical experience

We expect senior developers to be comfortable working with AI-assisted development practices, including:

• Experience using AI coding assistants and agent-based development approaches in software development

• Ability to provide structured context, specifications, and acceptance criteria for AI-assisted implementation

• Ability to critically review and validate AI-generated code, designs, and technical solutions

• Understanding of the opportunities, risks, and limitations of AI-generated output

• Experience leveraging AI to improve productivity, quality, testing, and documentation

• Interest in contributing to the evolution of AI-assisted engineering practices

Experience with tools such as Claude Code, Codex, GitHub Copilot, and related practices such as specification-driven development and AI-assisted testing is considered a strong advantage.

Interested?

Great! Send us your application via the system and tell us more about yourself. The position will be filled as soon as we find the right candidate.

If you have questions about the role, feel free to contact:

Pasi Jakonen
Head of Software Development
[email protected]