Archived listing. The details below describe a past opening.
The Principal Developer is a senior practitioner leader who operates at the intersection of hands-on engineering execution, software architecture, client-facing solutioning, and cross-functional program leadership. This role is designed for an engineer who can walk into any project environment, immediately understand what needs to be built and why, sequence the work, align the teams, and deliver. At the Principal level, this person drives application and platform engineering strategy for the organization, not just a single project. They set engineering standards, evaluate frameworks, languages, and architectural trade-offs, lead reference architecture decisions across engagements, and are the person RS21 turns to when a technical decision is hard. They translate ambiguous client requirements into scalable, maintainable software systems, own the full software development lifecycle from design through deployment and operations, and bridge the communication gap between business stakeholders, product teams, platform engineers, and data teams with equal fluency. This role further serves as an embedded technical program lead, with the discipline to decompose ambiguous initiatives into structured, sequenced delivery work, the systems thinking to connect every technical task to its business outcome, and the ownership to keep multi-workstream programs on track independently. As a people manager, the Principal Developer holds direct line management responsibility for a team of software developers. They own hiring, performance management, career development, and day-to-day people leadership for their team, ensuring engineers are growing technically while also being effectively staffed and supported across client engagements. Critically, the Principal Developer is a force multiplier. They raise the capabilities of those around them, train and coach junior and mid-level staff, establish the patterns and practices RS21's software engineering function grows from, and actively contribute to RS21's business development and proposal efforts as a credible technical voice.
Key Responsibilities
People Management
- Serve as the direct line manager for a team of software developers, designers and DevOps engineers owning staffing, workload balance, and day-to-day people leadership.
- Conduct regular 1:1s, set goals, and deliver formal performance reviews and feedback that support each team member's growth and accountability.
- Own hiring decisions for the team, including interviewing, candidate evaluation, and onboarding planning for new software developers.
- Identify and address performance issues proactively and fairly, partnering with HR and technical leadership as needed.
- Build individual development plans that align team members' career goals with RS21's technical roadmap and project needs.
Software Architecture & Engineering
- Drive RS21's application architecture strategy, evaluate frameworks, languages, and design patterns across engagements and make organization-wide recommendations.
- Design, build, and maintain production-grade, scalable applications and services, including APIs, backend systems, and front-end interfaces.
- Architect software systems with maintainability, testability, security, and performance built in from day one.
- Establish coding standards, architectural patterns, and engineering norms that apply across RS21's project portfolio.
- Ensure software reliability, performance, and scalability across applications, and hold teams accountable to those standards.
LLM Enablement & AI-Powered Application Development
- Evaluate and select foundation model and tooling strategies for RS21's AI and LLM-powered offerings; guide ethical AI approach across engagements.
- Design and implement application features that integrate LLM and AI capabilities, including:
- Conversational interfaces and agentic workflows
- Prompt orchestration, tool use, and function calling integrations
- Retrieval-augmented generation (RAG) integration within application layers
- Lead architecture decisions; drive integration patterns between application code and AI/ML services across projects.
- Ensure security, reliability, and responsible-use guardrails for AI-powered application features.
- Optimize application performance and user experience around LLM-backed features, including latency and cost trade-offs.
Cloud Architecture (AWS)
- Set RS21's cloud application strategy, evaluate multi-cloud trade-offs, drive AWS platform decisions, and contribute to reusable reference architectures for web applications, APIs, and event-driven systems.
- Architect and provision AWS services to support application workloads across ECS/EKS, Lambda, API Gateway, Step Functions, DynamoDB, RDS, S3, and EventBridge.
- Lead application security architecture, including IAM design, secrets management, and secure service-to-service communication.
- Partner with platform and DevOps teams to ensure secure, cost-effective, and scalable cloud deployments.
- Drive infrastructure-as-code, CI/CD, and automation practices; lead DevOps reliability strategy for application platforms.
Solutions Architecture & Client Engagement
- Lead discovery and requirements-gathering engagements with clients to translate ambiguous business and operational needs into concrete, scalable software architectures.
- Serve as RS21's primary technical face in client-facing software settings, capable of presenting to executive stakeholders and engineering teams in the language each audience needs.
- Produce reference architectures, solution design documents, and technical roadmaps that guide both client delivery and internal product development.
- Assess and document client technical readiness for modernization, AI adoption, and platform integration; identify gaps and prescribe actionable remediation paths.
- Own the technical narrative during solutioning, from pre-sales and scoping through delivery kickoff and handoff.
Technical Program Leadership
- Own end-to-end technical execution planning for software development workstreams. Define the sequence of work, identify dependencies, and ensure delivery milestones map to both technical and business outcomes.
- Operate as a technical program lead within project delivery: decompose complex initiatives into structured Jira epics, stories, and tasks with clear acceptance criteria; understand how every ticket fits into the larger program arc.
- Establish and continuously improve RS21's delivery standards for software engineering programs, translating lessons learned across engagements into stronger project management practices organization wide.
- Partner with project managers and product owners to ensure the technical execution plan stays aligned with contractual, operational, and business constraints.
- Lead planning, estimation, and review ceremonies with the technical authority to drive hard decisions to resolution when they arise.
- Serve as the central coordination point between client stakeholders, product teams, platform engineers, data engineering/data science teams, and DevOps, translating across all languages with fluency.
Product & Platform Support
- Support the evolving software architecture behind RS21's product and AI capabilities, including predictive and real-time, AI-enabled systems.
- Assess and improve internal and client application readiness for modernization, scaling, and AI adoption.
- Serve as the connective tissue across client stakeholders, product, platform engineering, data engineering, ML/data science, and DevOps teams, moving fluidly between business language and technical depth depending on who is in the room.
Staff Development & Org Capability
- Shape RS21's software engineering talent strategy, anticipate capability gaps before they become program risks, and partner with technical leadership on the hiring, development, and structural decisions needed to close them.
- Train, mentor, and grow junior and mid-level developers in both technical depth and architectural thinking.
- Build the onboarding frameworks, internal playbooks, and knowledge-transfer practices that make RS21's software engineering capability portable, consistent, and independent of any single person.
- Conduct code reviews, architecture reviews, and design critiques that elevate team output quality and raise the floor of what RS21 ships.
- Model big-picture thinking, help the team understand not just what to build, but why it matters and how it connects to client outcomes and RS21's broader technical strategy.
Collaboration & Communication
- Collaborate closely with data engineers and data scientists building AI and analytics features to ensure application architecture meets data and model requirements.
- Shape how RS21 communicates with technical and executive audiences, influencing clients through evidence-based, decision-driving narratives.
- Hold the full system in view across the organization, client, and market; shape decisions with long-horizon thinking.
- Document software architectures, APIs, and best practices to support transparency and reuse.
- Contribute to RS21 business development, proposal efforts, and technical volume authorship as a credible senior voice.
Qualifications
Required
- Bachelor's degree or equivalent experience in computer science, software engineering, or a related field.
- 7+ years of hands-on software development experience, with at least 3 years in a senior, lead, or architect-level capacity.
- Prior experience directly managing software developers, including hiring, performance management, and career development.
- Deep, hands-on experience with modern application architectures, including microservices, API design, and event-driven systems.
- Demonstrated proficiency in one or more backend languages (e.g., Python, Java, TypeScript/Node.js, Go) and modern front-end frameworks (e.g., React).
- Proven ability to design and deliver production-grade, scalable applications and services on AWS, using services such as ECS/EKS, Lambda, API Gateway, DynamoDB, RDS, and S3.
- Demonstrated experience integrating LLM, AI, or machine learning capabilities into applications, including RAG patterns, agentic workflows, or AI service orchestration.
- Track record of client-facing work: requirements gathering, stakeholder communication, and translating business needs into scalable technical solutions.
- Experience functioning as a technical program lead owning delivery plans, managing Jira-based project tracking, and coordinating cross-functional technical teams.
- Strong architectural reasoning and systems thinking, able to hold the full picture while executing in the details.
- Excellent written and verbal communication skills with demonstrated ability to adapt technical depth to audience.
Preferred
- AWS certifications: Solutions Architect – Professional, Developer – Associate, or equivalent.
- Experience with infrastructure-as-code tools (Terraform, CDK, or similar) and DevOps/CI-CD practices.
- Background in consulting, professional services, or multi-client delivery environments.
- Familiarity with containerization and orchestration (Docker, Kubernetes) at production scale.
- Experience with testing frameworks, observability tooling, and performance optimization at scale.
- Exposure to DoD, federal, or regulated-sector software environments; FedRAMP-compliant architecture experience a plus.
