Solutions Architect

Apex Systems, LLC; Costa Mesa (CA); Hybrid; USD 170,000 - 210,000; Full time

Job summary

Apex Systems, LLC is seeking a Senior Solutions Architect with 8+ years in software architecture and hands-on coding, including recent production work on LLM agent systems.

The candidate will work on identity, payments security, threat modelling, ADRs, and partner-facing technical sessions, with familiarity in CDN/edge architectures and modern privacy by design practices.

Qualifications

• 8+ years in solutions or software architecture with hands-on coding.
• Recent production work on LLM agent systems with tool use.
• Familiarity with major AI platforms and Context Protocols.

Responsibilities

• Lead architecture discussions and present ADRs to stakeholders.
• Collaborate with external engineering teams in technical reviews.
• Design secure identity and payments flows for integrated solutions.

Skills

Solutions architecture

Software architecture

LLM agent systems

Tool use

Identity & payments security

Tools

Messages API

Agent SDK

Managed Agents

Model Context Protocol

OAuth 2.0 / OIDC

JWT/JWKS

PCI checkout

CDN/edge architectures

Job description

## Job Description# Solutions Architect* 8+ years in solutions or software architecture with hands-on code experience, including recent production work on LLM agent systems with tool use.* Working knowledge of a major AI platform (Messages API tool use, prompt caching, Agent SDK, Managed Agents) and the Model Context Protocol, including authenticated MCP servers.* Experience with identity and payments architecture: OAuth 2.0 / OIDC, JWT/JWKS, HTTP message signatures, and PCI-adjacent checkout flows. Familiarity with agentic-commerce protocols and KYA concepts is required.* Experience with threat-modelling and privacy-by-design, with the ability to write ADRs and sequence diagrams for technical and partner audiences.* Consulting-grade communication skills, with experience leading technical working sessions with external engineering teams.* Verifiable Credentials (W3C VC 2.0, OID4VCI/OID4VP, SD-JWT or BBS+).* Experience with fraud/risk decisioning platforms.* Knowledge of CDN/edge architectures (e.g., Cloudflare Workers).* Prior experience in a forward-deployed or FDE role.