I'm Abhishek Kumar

Backend Developer — AssistArmy

Digital Human Interface (DHI) AI Startup · Bangalore

Digital Human Interface (DHI) Platform

• Worked on backend services powering real-time AI avatar interactions across web, mobile, and feature phone clients
• Contributed to REST APIs using Spring Boot & Microservices architecture for multi-modal interaction (text, voice, visual)
• Contributed to modular service design enabling rapid feature iteration in an early-stage product environment
• Helped standardize API contracts and request/response models across services using Swagger/OpenAPI documentation

LLM & GenAI Integration

• Assisted in integrating OpenAI LLM APIs into the conversation flow — supporting prompt formatting, response parsing, and downstream service handling
• Worked on guardrails and validation layers around LLM responses to ensure consistent and safe outputs in production
• Contributed to RAG-based context-passing logic for improved response relevance in user conversations
• Assisted in tuning prompts and chaining logic to reduce response latency in real-time interactions

Real-Time Communication & APIs

• Worked on WebSocket-based modules enabling bidirectional communication between clients and backend services
• Helped implement connection handling, heartbeat checks, and reconnection logic to improve session stability
• Contributed to REST endpoints with input validation, structured error handling, and standardized response patterns

Security, Reliability & Deployment

• Contributed to Spring Security with JWT-based authentication, role-based access control, and request rate limiting
• Wrote unit and integration tests using JUnit & Mockito and participated in code reviews with senior engineers
• Worked with Docker for local development setup and supported CI/CD pipeline tasks for staging deployments
• Collaborated with frontend, AI, and DevOps teams to ship features in 1–2 week release cycles

Tech: Java 21, Spring Boot, Spring Security, REST APIs, WebSocket, OpenAI APIs, MySQL, Docker, Git, Microservices

Backend Developer — Speedbae

E-commerce Last-Mile Delivery Startup · Jamshedpur

Order Management Service

• Worked on end-to-end Order lifecycle (Placed → Confirmed → Packed → Dispatched → Delivered) using Spring Boot & Microservices architecture
• Contributed to REST APIs consumed by mobile and web clients with standardized request/response contracts
• Helped optimize JPA queries and resolve N+1 issues, improving order processing latency in production workflows
• Helped standardize exception handling and structured error responses across services, improving API reliability

Inventory & Tracking Module

• Contributed to inventory reservation flow handling SKU-level stock updates with transactional safeguards
• Worked on real-time delivery tracking pipeline writing location updates to Cassandra with time-series partitioning
• Assisted in building APIs powering live ETA updates on the mobile client through WebSocket-based communication

Last-Mile Delivery & Reliability

• Contributed to delivery agent assignment and slot management APIs to reduce unassigned order backlog
• Assisted in implementing failure-reason logging and retry workflows improving re-attempt success in failed deliveries
• Wrote unit and integration tests using JUnit & Mockito, ensuring stable behavior across releases
• Collaborated with QA, Backend & DevOps teams for controlled staging and production deployments using Docker & Jenkins

Tech: Java, Spring Boot, JPA/Hibernate, MySQL, Cassandra, REST APIs, WebSocket, Docker, Jenkins, Git