The Problem #
A SaaS company providing digital marketing and data privacy compliance solutions for European clients had a legacy backend with:
- Low test coverage, leading to frequent production bugs
- Monolithic architecture without layer separation, making it hard to maintain and extend
- Manual deployment process that was error-prone
The Solution #
Complete backend refactoring to a service–repository pattern using Go and PostgreSQL.
Key Changes #
- Service–repository architecture: separating business logic from data access, improving testability and maintainability
- RESTful API development: new endpoints to support digital marketing and data privacy workflows
- Automated testing: gradually increasing test coverage from baseline to 75%
- CI/CD integration: cross-functional team collaboration using Jira, Bitbucket, and Slack
Results #
- Test coverage up to 75%: from a very low baseline
- Production bugs down 40% between Q3–Q4 2024
- More reliable deployments: new features and bug fixes delivered on schedule
- More readable code with significantly reduced onboarding time for new developers
Lessons Learned #
- Test coverage isn’t a number, it’s a safety net: the investment in automated testing pays off when every deployment can be done with confidence, not hope
- Service–repository pattern is an investment: despite higher upfront cost, layer separation makes debugging, testing, and feature addition far easier once the foundation is in place
- Cross-functional collaboration: regular communication via Jira and Slack with non-technical teams ensures what’s built matches what’s needed