Senior Back-end Developer (Ruby on Rails)
Emilii Plater 53, Warszawa
Sigma Software
We’re looking for a Senior Back-end Developer to design and implement reliable, scalable, high-performance systems and collaborate closely with our engineering teams to deliver robust solutions that drive real impact.
At the heart of what we do is a simple mission: to deliver an asymmetric advantage to our AdTech Сustomers through deep expertise, simplicity, and exceptional service. We challenge ourselves to grow – as technologists, professionals, and teammates who support one another every step of the way.
Our culture is built on dedication, trust, and continuous improvement. We celebrate success together, learn from our failures, and take pride in delivering outstanding results for our clients.
If this sounds like the kind of environment where you’d thrive – join us and help build what’s next.
CUSTOMER
Our Customer provides a novel approach to office meals. Through their platform, customers get automated and organized lunches, serving individual and customizable meals to offices from restaurants. They offer their customers a competitive advantage through their extensive industry knowledge, straightforward process, and a high level of service.
The Customer is extremely open to the team’s professional opinion, so you will have a chance to initiate changes and improve the existing solution.
Requirements
Experience with Ruby on Rails (Back-end)
5+ years of solid software engineering experience
Experience designing and implementing scalable, cloud-based architectures for production-grade Back-end (preferably, have experience with AWS, EC2 load balancing, auto-scaling, CloudWatch, and Aurora)
Experience with database engineering, including SQL/GraphQL with million-size relational records (preferably, the ability to write and optimize PostgreSQL and GraphQL)
Ability to design relational schemas appropriate for given use cases
In-depth understanding of the fundamentals of web technologies, data structures, and algorithms
Upper-Intermediate level of English
Will be a plus:
Strong development skills in languages such as JavaScript, Ruby, and Python, preferably with a solid background in modern web stacks)
Experience operating relational databases at scale
Personal Profile
Great communication skills, including written and verbal communication
Strong time management and prioritization skills, with the ability to work independently
Demonstrated sense of ownership and accountability in delivering high-quality results
Responsibilities
Design and implement solid, scalable, and flexible Back-end systems
Collaborate with Front-end engineers and QAs to deliver new features together with team members on the client side
Maintain a healthy Back-end services and a high level of quality
Design and implement unit tests and highly maintainable code
Generate great new ideas for features and better ways to implement existing ones
Take an active part in team meetings and ceremonies

Sigma Software is a global software development company founded in 2002. It enables enterprises, startups, and product houses to meet their technology needs through end-to-end delivery, providing top-quality software dev...
Senior Back-end Developer (Ruby on Rails)
Senior Back-end Developer (Ruby on Rails)
Emilii Plater 53, Warszawa
Sigma Software