Back End Developer - Contractor

We are looking for a senior-level backend contractor to help improve and evolve several production services by refactoring them toward a clearer, domain-oriented. The work will focus on improving service boundaries, simplifying complex business logic, and making key workflows easier to understand, test, and extend. One important area involves rules-based processing, alarm generation, and user notification flows. Another involves authorization and access-control related services.

The system processes tens of millions of messages per hour across Kafka-backed services and must remain reliable, observable, and maintainable under sustained.

• Refactor existing backend services toward clearer domain boundaries and more
• Improve complex business workflows related to rules, alarms, notifications, authorization, and access control.
• Help separate domain logic from infrastructure and integration concerns.
• Improve testability, reliability, and operational clarity.
• Work incrementally within existing production systems without unnecessary rewrites.
• Collaborate with the engineering teams on design decisions, tradeoffs, and rollout plans.

• Senior-level backend engineering experience with production business applications.
• Strong experience refactoring complex services or legacy codebases.
• Practical understanding of domain-driven design, clean architecture, or similar approaches.
• Experience with distributed systems and event-driven architectures.
• Experience with Kafka or comparable messaging systems.
• Strong database and caching experience.
• Experience with service-to-service APIs such as gRPC, REST, or similar.
• Ability to reason about reliability, idempotency, retries, failure modes, and operational behavior.
• Strong communication skills and ability to work independently as a contractor.

• Experience with authorization, access control, rules engines, alerting, notifications, workflow systems, or similar business domains.
• Experience with high-volume production systems.
• Experience improving observability, testing strategy, and rollout safety.

• The ideal candidate is a pragmatic senior engineer who can quickly understand an existing system, identify useful refactoring opportunities, and make meaningful improvements without disrupting production behavior.

We are an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability or protected veteran status. The work environment characteristics, and any physical and mental requirements described here are representative of those that must be met by an employee to successfully perform the essential functions of this job.

Reasonable accommodations may be made to enable individuals with disabilities to perform the essential functions.