An in-depth review of the system designs, challenges, and core solutions.
Automated candidate hiring CRM with LLM tool calling
A premium full-stack HRMS where HR teams create job forms, manage applicants, and onboard candidates via an interactive CRM interface. Integrates an Ollama LLM with tool-calling capabilities to autonomously send emails and update statuses through chat.
Configuring Ollama's local LLM tool calling on EC2 with stable latency. Resolving this required implementing model parameter optimizations and a robust queue system for background processing of candidate emails and CRM status updates.
Deepened knowledge in vector databases (pgvector), building resilient AI agent loops using Spring AI, and managing AWS EC2 scale-ups for hosting local models.
Highly concurrent multiroom chat engine
A highly responsive real-time chat application with a clean UI, enabling instant room creation, room joining, and concurrent user messaging. Includes full message history persistence.
Handling concurrent connection spikes and message delivery order consistency. Addressed by designing a custom message buffer and thread-safe session handlers in Spring Boot.
Mastered WebSocket protocols, state sync between client/server, and local multi-container orchestration with Docker.
HTTP request upgraded to WS protocol using SockJS fallback support.
Subscribes client to specific chat-room routing endpoints (e.g. /topic/room).
Bidirectional message streaming with DB persistence for history retrieval.