Senior Database & Backend Developer – .NET, Azure SQL & NoSQL

Are you a software professional and want to be a part of a company that’s changing the game in the world of HR software? Does joining one of Europe's most established HR tech companies backed by tier one investors sound exciting to you? We are growing and are looking for a Senior Database & Backend Developer – .NET, Azure SQL & NoSQL to join our Engineering organization. 
  
Type: Full-time, permanent  
Location: Espoo or Lahti, Finland 
Hybrid: 1-2 days a week at the office
Starting date: As soon as possible  

 
Sympa helps some of the largest companies in the Nordics to put people at the centre of their strategy. With 1,000 customers and a strong install base, we have a strong foundation for continued growth. Our Engineering hubs are in Vantaa (Espoo beginning of June 2025), Lahti, and Poland and you would be part of a highly talented and international team of over 55 engineering colleagues.   

 
Our solution is built on Microsoft Azure, the technologies we currently use to build our service include .NET and React as primary technologies, Domain-Driven architecture and API First design principles, Azure Compute, Messaging and Data Services, along with various SQL and NoSQL databases. 

As a Senior Database & Backend Developer, you will have a pivotal role in Sympa’s development team specializing in database technologies while also contributing to backend development. You will take ownership of database performance, schema design, data migrations, and optimizations, ensuring efficient and scalable data solutions. With your expertise in various databases, you will contribute hands-on to developing .NET/C# applications that leverage them. You will work closely with software architects, backend developers, and DevOps teams to optimize database interactions and maintain high system performance. You’ll get to work hands-on with latest technologies, tools and frameworks and challenge your problem-solving skills in a flexible and agile working culture with a team that is talented, supportive and fun. 

 
Your key responsibilities as a Senior Database & Backend Developer

• Database Administration & Optimization: 

  • Design, implement, and optimize SQL database structures, including schema changes, indexing strategies, and query performance tuning. 

  • Work with NoSQL and graph/document databases (e.g., Cosmos DB, MongoDB, JanusGraph and Gremlin) to ensure efficient data modelling and performance. 

  • Monitor and troubleshoot database performance issues, ensuring high availability and efficiency in a production environment. 

• Data Migrations & Backend Integration: 

  • Plan and execute large-scale data migrations, ensuring minimal downtime and seamless application transitions. 

  • Assess the impact of database changes on the .NET/C# codebase and modify backend logic accordingly. 

  • Create migration tools and modify ORM mappings when necessary. 

  • Coordinate database migration project testing and execution and ensure system stability afterwards with needed monitoring capabilities 

• Backend Development & Code Optimization: 

  • Identify and optimize inefficient database queries embedded in .NET applications. 

  • Work with development teams to refactor database-heavy application logic and improve overall efficiency. 

  • Optimize database access with efficient queries, batching, caching, and connection management to improve performance, reduce load, and ensure scalability

• Collaboration & Deployment: 

  • Work closely with software architects to design scalable and maintainable database solutions. 

  • Collaborate with DevOps teams to ensure database changes are smoothly integrated into CI/CD pipelines. 

  • Implement monitoring and observability solutions for database health using Open Telemetry, Grafana, Azure Monitor, Application Insights, and Log Analytics. 

• Process & Knowledge Sharing: 

  • Conduct code reviews focused on database interactions and performance. 

  • Train and mentor developers on database best practices and efficient query writing. 

  • Stay up to date with industry trends in database technologies and recommend improvements. 

What do we value in our candidates?  

The person we are looking for has vast technological background, is highly motivated, curious and able to take challenges and responsibility from day one. You have great self-discipline, and you make things happen. You are also a strong team player, willing to spread your technical excellence to your team and willing to help others in technical problems.  
  

Furthermore, the following skills and experience will help you to succeed:   

• Several years of experience in database administration and backend development with expertise in .NET and C# 

• Strong experience in SQL Server, including query optimization, stored procedures, schema design and indexing 

• Proficiency in NoSQL databases (e.g. Cosmos DB, MongoDB) and graph/document models 

• Ability to analyse and improve database-heavy .NET code, making performance-driven enhancements 

• Experience executing large-scale data migrations in live environments 

• Familiarity with Azure cloud services, including Azure SQL, Cosmos DV and manages database solutions 

• Expertise in production monitoring tools such as Open Telemetry, Grafana, Azure Monitor, Application Insights and Log Analytics 

• Knowledge of CI/CD pipelines and infrastructure automation is a plus 

• Excellent communication skills and ability to work collaboratively with development teams 

• Problem-solving and analytical skills with a proactive approach to identifying database performance bottlenecks 

• Degree in computer science, engineering or related  

Why Sympa?   

Sympa is striving for fast international growth while maintaining the agility of a small business, and this shapes our work culture. Decisions are made fast, with flat hierarchy, and everyone who works at Sympa is valued for themselves and for their skills. We’re all connected by a passion for what we do, and a desire to develop in what we do, and we have the freedom to create, implement and grow together with Sympa.   
  

• Innovation: Work with the latest technologies and tools in the industry.   

• Collaboration: Join a diverse team of talented Sympaticans who thrive in our agile and flexible work culture.   

• Impact: Make a meaningful contribution to our customers' success.   

• Benefits: Take advantage of perks such as lunch and cultural activities   

• Growth: Be part of a company that values your skills and supports your development.   

  
Got your attention?   

Great, now let us know who you are by sending us your CV and a short application letter. We’d like you to outline your salary expectations and potential starting date in your cover letter. The position will be filled as soon as we find the right candidate.   
   
If you have any questions on the role, you can contact our hiring manager, Pasi, for this position.   

Pasi Jakonen   

Head of Software Development 

pasi.jakonen@sympa.com

Sympa believes an equal, diverse, and inclusive work environment leads to a creativity, innovation, and openness- everything we value on our global growth journey.

 
We commit to providing equal opportunity to all qualified applicants regardless of gender, gender identity, age, nationality, religion, disability, sexual orientation, or any other personal characteristics.

We want everyone to be themselves and to thrive in our inclusive work environment.