Principal Software Engineer - Modernization

Karsun Solutions, LLC•Herndon, VA

6h•$170,000 - $180,000

About The Position

Join Karsun Solutions to grow your career with the company transforming possible for the US Government. At Karsun, collaboration drives our community. We’re committed to building an environment where team members from diverse backgrounds can innovate, learn and grow with us. Here at Karsun, the only limit to your potential is the limit of your curiosity. Join Team Karsun, and Find Your Next! Summary Lead the modernization of large Java/Spring Boot monoliths in AWS into a secure, scalable microservices target state; define microservices archetypes, coding standards, error-handling and messaging patterns, introduce and scale caching (Redis), and mentor development team leads while collaborating closely with SRE in a mature containerized CI/CD environment for a federal program.

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.

Nice To Haves

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.

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.