Senior Backend Engineer – Model Gateway & Backend Architecture

Role Overview

Smack Technologies builds mission‑critical AI systems that operate in classified, on‑prem, and edge environments. As a Senior Backend Engineer on Applied Engineering, you will own the design, implementation, and evolution of the backend systems that power Smack’s products, with primary responsibility for the model gateway and core backend architecture.

This role focuses on turning research outputs into production systems that are reliable, secure, and operable in TS/SCI environments. You will design the backend services that expose model capabilities to operators, enforce access controls, manage data flow, and support real‑world mission workflows.

You are expected to own systems end‑to‑end, from architectural decisions through production behavior and incident response.

Own the architecture and implementation of Smack’s backend services, with a primary focus on the model gateway serving LLMs, reinforcement learning agents, and knowledge graph components.

Design stable, secure APIs that expose model capabilities while enforcing RBAC, data provenance, and auditability requirements.

Translate research artifacts into production‑grade services suitable for TS/SCI, IL-7, and on‑prem deployments.

Design backend systems that support evaluation infrastructure, telemetry, logging, and feedback loops used to improve model performance over time.

Partner closely with Dev Ops and platform engineers to ensure backend services are deployable, observable, and reliable in restricted environments.

Own backend performance, scalability, and failure modes, including graceful degradation and clear error semantics.

Participate in on‑call rotations, incident response, and root‑cause analysis for deployed systems.

Collaborate with frontend, UX, and mission teams to ensure backend behavior aligns with operator workflows and constraints.

Set backend standards and technical direction across Applied Engineering.

• Active TS/SCI clearance
• Senior‑level experience designing and operating backend systems in production
• Strong experience with service‑oriented or API‑driven architectures
• Proven ownership of critical backend systems end‑to‑end
• Proficiency in at least one production backend language (Python, Go, Java, or similar)
• Experience building data‑intensive or compute‑heavy services
• Strong understanding of authentication, authorization (RBAC), and secure service design
• Experience operating backend systems in constrained or regulated environments
• Ability to reason about system behavior under load, failure, and partial degradation
• Experience working in fast‑moving environments with real operational consequences

• Backend Development: Python, Go, or similar
• API Design: REST and/or gRPC, versioning, schema evolution
• Model Gateway Concepts: request routing, batching, rate limiting, model versioning
• Data & State: databases, caches, message queues
• Observability: Open Telemetry, metrics, logging, tracing
• Security: RBAC, service‑to‑service auth, secrets management
• Deployment Contexts: TS/SCI, IL-7, on‑prem
• Operational Readiness: performance tuning, incident response, root‑cause analysis

• Experience building or operating model‑serving platforms
• Familiarity with LLMs, RL systems, or knowledge graphs at the systems level
• Experience supporting evaluation or experimentation infrastructure
• Prior work closely integrating research into production systems