ARCHITECTURE & SYSTEM DESIGN

Four sanitized views of how the systems fit together.

Each diagram states the job, the components, the data flow, the decision, the constraint and the trade-off. No confidential employer internals.

1. AI Agent with RAG and tools

Job: answer an operational question or propose a controlled action without giving the model raw system access.

User, agent, orchestration, RAG, tools, REST User AI Agent Orchestration RAG MCP tools REST services

Flow: prompt → agent → orchestrator → retrieve or tool → REST. Decision: fail closed on empty retrieval. Constraint: no secrets in prompts. Trade-off: fewer tools, more human confirmation, slower autonomy.

2. Real-time messaging workflow

Job: deliver a message and call state to the other client with a known failure mode, not a silent drop.

Client A to API to realtime to Client B Client A API Persist / ack Realtime Push / WS Client B

Components: clients, API, persistence, realtime fan-out, push. Decision: persist before fan-out. Constraint: offline clients. Trade-off: stronger delivery guarantees vs. fan-out cost.

3. B2B organization and web-admin model

Job: one company tenant, one admin control plane, many employee devices.

Company tenant to web admin to employees Company tenant Web Admin Employees · mobile Roles / RBAC

Flow: tenant config → admin writes policy and content → employees read/write inside role scope. Decision: organization is the tenancy unit. Constraint: admin is not a second product. Trade-off: mobile-first daily UX vs. denser admin tables.

4. API integration lifecycle

Job: take an unclear integration request to a contract that engineering can implement and QA can accept.

Discover design contract prototype accept Discover Design API contract Prototype Accept

Components: stakeholders, requirements, OpenAPI/JSON schemas, PoC, UAT. Decision: contract before code. Constraint: existing systems are not rewritten. Trade-off: slower start, fewer integration surprises.