Back-End Developer (Swedish Ad Platform)

Company Description

Are you a skilled Back-End Developer with a passion for building scalable, high-performance platforms? Join Sigma Software and contribute to the transformation of a global AdTech product into a modern, API-driven architecture.

This is a Middle/Senior-level role with a remote-friendly setup, giving you flexibility while working with cutting-edge technologies. We at Sigma Software value engineering excellence, innovation, and collaboration, offering opportunities to work with world-class customers and impactful projects.

Why join us? You will work on a platform trusted by top-tier publishers, gain exposure to advanced serverless architectures, and be part of a team that encourages professional growth and continuous learning.

CUSTOMER

Our Customer is a Sweden-based AdTech company specializing in advanced self-serve advertising platforms that automate direct transactions between advertisers and major global publishers. Their technology removes traditional friction in ad sales by enabling automation, transparency, and operational efficiency at scale. Platforms are trusted by internationally recognized publishers including TripAdvisor, Bloomberg, The Washington Post, Opera, and Dow Jones, handling millions of transactions worldwide.

PROJECT

The project is a strategic architectural transformation toward a Platform-First approach. The company is transitioning from monolithic, client-specific implementations to a standardized, API-driven, multi-tenant ecosystem of reusable microservices. These services power the entire product suite, remaining independent, scalable, and decoupled from frontend or customer-specific customization.

Key Technologies: TypeScript, Node.js, AWS Lambda, API Gateway, DynamoDB, EventBridge, IaC tools (CloudFormation or Terraform), RESTful/GraphQL APIs.

Job Description

• Develop and maintain high-performance microservices using TypeScript and Node.js in a serverless AWS environment
• Collaborate on API design and maintain OpenAPI specifications
• Implement scalable solutions with AWS Lambda, API Gateway, DynamoDB, and EventBridge
• Ensure strict tenant data separation and adherence to established AdTech data models
• Contribute to shared libraries, reusable templates, and engineering best practices
• Participate in code reviews focusing on performance, reliability, and observability
• Translate product requirements into technical specifications
• Support the evolution of the platform toward standardization and reusability

Qualifications

• 3+ years of production experience as a Back-End Developer
• Solid hands-on skills with TypeScript and Node.js
• Experience with API-first microservice architectures
• Familiarity with AWS serverless tools (Lambda, API Gateway, DynamoDB, EventBridge)
• Understanding of RESTful and GraphQL APIs
• Knowledge of multi-tenant architecture and logical data isolation
• Interest in AdTech concepts and workflows
• Upper-Intermediate English level

WILL BE A PLUS

• Experience with Infrastructure as Code tools (CloudFormation, Terraform)
• Knowledge of CI/CD pipelines and deployment automation
• Familiarity with event-driven architectures
• Understanding of observability tools (CloudWatch, X-Ray, etc.)

Additional Information

PERSONAL PROFILE

• Strong problem-solving mindset
• Ability to work in a collaborative, cross-functional team
• Attention to detail and commitment to code quality
• Proactive in proposing improvements and optimizations