Principal Software Engineer - Modernization

Karsun Solutions is transforming possibilities for the US Government. They are seeking a Principal Software Engineer to lead the modernization of large Java/Spring Boot monoliths into microservices, define technical strategies, and mentor development teams.

Responsibilities:

• Own technical strategy and roadmap for migrating Java/Spring Boot monoliths to microservices using incremental refactor and strangler patterns
• Define and enforce microservices archetype(s): project structure, common libraries, API contracts, logging/trace conventions, retry/backoff, idempotency, and fault-tolerance
• Specify and enforce coding standards, error-handling, message formats, and async integration patterns (events, queues, sagas)
• Design service boundaries, data partitioning, versioning, and database migration strategies; coordinate polyglot persistence where allowed
• Introduce, design, and scale caching strategies (Redis, in memory caches) for performance and consistency; implement cache invalidation, replication, and high-availability patterns
• Collaborate tightly with SRE teams to align on CI/CD pipelines, container images, runtime configuration, resource policies, observability (metrics, logs, traces), alerting, and incident runbooks
• Lead hands-on refactors of production systems and provide code-level reviews and guidance for complex migrations
• Ensure microservices are production-ready for a mature containerized environment (Docker, Kubernetes/EKS), and integrate with existing CI/CD and security scanning workflows
• Resolve high-priority production incidents, lead RCA, and implement long-term mitigations
• Mentor and coach development team leads across multiple squads (30+ developers), improve engineering practices, and manage technical tradeoffs under pressure
• Coordinate with product owners, security officers, and federal stakeholders; provide estimates, risk mitigation, and progress reporting

Requirements:

• Bachelor's Degree in Computer Science or equivalent
• 10+ years software engineering experience; 5+ years leading monolith→microservices modernization in production
• Demonstrated federal experience delivering software for U.S. federal agencies or contractors
• Must be able to clear and hold a Public Trust clearance (suitability adjudication)
• Deep expertise in Java and Spring Boot; experience integrating with Angular frontends
• Strong experience in containerized, production Kubernetes environments and mature CI/CD pipelines
• Proven track record defining microservice archetypes, coding standards, error-handling, and messaging patterns at scale
• Experience introducing and scaling caching solutions (Redis) in production, including HA, replication, and cache-invalidation strategies
• Experience working closely with SRE/platform teams on observability, deployments, runtime configuration, and incident management
• Experience coordinating engineering efforts across 30+ developers
• Proficiency with AWS (EKS/ECS/Lambda, API Gateway, RDS/Aurora, S3, SNS/SQS), IaC (Terraform/CloudFormation), and CI/CD tooling
• Excellent leadership, mentoring, and stakeholder management skills
• Active federal clearance (preferred)
• Experience with event-driven architectures, saga patterns, and large relational schema refactors
• Familiarity with observability stacks (Prometheus/Grafana, Datadog), distributed tracing (OpenTelemetry), and chaos/resilience testing
• Prior experience defining shared platform libraries and developer onboarding for microservices