Abhirama abhiramaab

Abhirama

Self-Taught Backend Developer · Building scalable, reliable distributed systems.

Distributed Systems • Backend Engineering • Cloud Infrastructure

Architecture & System Design: System Design (HLD & LLD), Idempotency, Distributed Mutex Locks, Transactional Outbox Pattern, Consistent Hashing, Double-Entry Ledger, Token-Bucket Rate Limiting
Languages & Frameworks: Java (8/17/21), Spring Boot, Spring MVC, RESTful APIs, Microservices
Distributed & Data Stores: PostgreSQL, MySQL, Redis, Spring Cloud (Eureka, Gateway, OpenFeign)
Security & Identity: Spring Security, JWT, OAuth 2.0, RBAC
Cloud & Tooling: Docker, AWS (EC2), Linux, Git, Maven, JUnit 5

Spring Cloud (Merged): Implemented Azure DevOps Workload Identity authentication in Spring Cloud Config JGit HTTP transport (+706 lines).
codecentric / spring-boot-admin (Merged): Configurable browser notifications timeout and click-through deep-linking to instance details for single-instance status changes (Issue #5504, +148 lines).
Apache Camel (Merged): Resolved Kafka record key preservation across HTTP hops in kafka-sink Kamelet.
Apache Shiro (Merged): Resolved Active Directory user principal name binding bug (merged in release 3.0.1).
Apache Hop (Merged): Fixed Hop Web stalled session bug via ServerPushSession UI keepalive and suppressed redundant HTTP wire logs.
Kestra (Merged): Fixed MCP client auto health-check socket leaks in core engine and added enum validation for Telegram plugin.
Jenkins: Resolved URL percent-encoding in Jira Cloud plugin; eliminated workspace polling in Workflow SCM Step plugin.

High-throughput payment gateway orchestrator tackling race conditions, event delivery, and accounting.

System Design & Architecture Breakdown

Idempotency & Distributed Locks: Uses Redis SET NX EX with double-checked idempotency keys to guarantee payments are processed exactly once and prevent duplicate charges during concurrent clicks.
Transactional Outbox Pattern: Writes payment events directly to an outbox table in the same database transaction, with a background worker relaying webhooks so messages never drop during network failures.
Double-Entry Ledger: Records debits and credits for every transaction to keep account balances audit-proof.
Consistent Hashing Router: Uses a 360° virtual node ring in memory (TreeMap) to balance merchant traffic across servers and handle node crashes cleanly.
Automated Reconciliation: Runs a scheduled job to detect and fail out payments that got stuck in PROCESSING after 5 minutes.

Workspace automation and autonomous agent platform connecting Gmail, Google Calendar, GitHub, and unified search into one interface.

Stack: Java 21, Spring Boot 3.5, Spring Security, PostgreSQL (Neon), OpenAI GPT-4.1-mini, Docker, AWS EC2, HTTP/2, React 18
Links: Live Platform · Documentation

System Design & Architecture Breakdown

Deterministic Agent Router: Uses an intent classifier to route structured queries directly (bypassing LLMs for sub-100ms response times) and delegates complex multi-step goals to an agent planner.
Parallel Tool Executor: Executes external API requests across Gmail, Google Calendar, and GitHub concurrently using Java virtual threads and CompletableFuture.
Secure Token Lifecycle: Encrypts multi-provider OAuth refresh tokens using AES-256 before database persistence and handles automatic token rotation without dropping active sessions.
Incremental Mailbox Sync: Ingests changes using Gmail history tokens and delta updates instead of polling full mailboxes, saving network bandwidth and database write load.
Unified Semantic Search: Consolidates queries across emails, thread attachments, GitHub PRs, and upcoming calendar meetings in one indexed pipeline.

Logistics and fleet dispatch management platform built for vehicle tracking, driver allocation, and operational control.

Stack: Java 21, Spring Boot 3, Spring Data JPA, Spring Security, JWT, React, TypeScript, Tailwind CSS
Links: Live Platform · Code · Documentation

System Design & Architecture Breakdown

Dispatch Orchestration: State-driven trip transitions (PENDING -> ASSIGNED -> IN_TRANSIT -> DELIVERED) ensuring drivers and vehicles are never double-booked.
Fleet Telematics & Maintenance: Logs vehicle operating metrics, fuel consumption ledgers, and scheduled preventative maintenance windows.
Automated Billing Engine: Triggers customer freight invoice generation immediately upon delivery fulfillment with receipt dispatches.
Decoupled Security: Enforces role-based access control (RBAC) and stateless HMAC-signed JWT filters separating drivers, dispatch coordinators, and financial auditors.

Write clean code. Understand the system from first principles. Ship consistently.