Shiv Kumar

Architecture portfolio

Open-source reference architectures and implementations. Each repository has design documents, architecture decision records, diagrams, tests, Docker and CI.

Architecture & distributed systems

How large systems are shaped: patterns, events, tenancy and trade-offs.

• system-design-architecture

  Twelve reference system designs with capacity models, ADRs and diagrams: video, messaging, feeds, job portal, e-commerce, multi-tenant SaaS and enterprise AI.

  • system design
  • capacity planning
  • ADRs

• microservices-patterns

  A catalogue of 17 microservices patterns with TypeScript implementations: saga, outbox, CQRS, event sourcing, circuit breaker, bulkhead and idempotency.

  • microservices
  • saga
  • CQRS

• event-driven-platform

  Three services that talk only through RabbitMQ events, with a transactional outbox, idempotent consumers, retries and dead-letter queues.

  • RabbitMQ
  • outbox
  • TypeScript

• enterprise-saas-platform

  Multi-tenant SaaS foundations: PostgreSQL row-level security, tenant-aware auth, RBAC, entitlements, audit logs and rate limits.

  • multi-tenant
  • row-level security
  • RBAC

EAM & real-time systems

Asset-heavy operations: work orders, maintenance and live telemetry.

• eam-platform-architecture

  Enterprise Asset Management reference architecture: work-order lifecycle, preventive and predictive maintenance, asset hierarchy, field service and maintenance KPIs.

  • EAM
  • FSM
  • domain-driven design

• realtime-monitoring-platform

  MQTT ingestion, Redis Streams or Kafka, alerting with hysteresis, PostgreSQL time series and a live WebSocket dashboard.

  • MQTT
  • Kafka
  • IoT telemetry

Generative & agentic AI

LLM systems that cite their sources, respect permissions and ask before acting.

• rag-enterprise-assistant

  Retrieval-augmented generation over company documents: hybrid vector and BM25 search, pgvector, access-controlled retrieval, citations, guardrails and evaluation.

  • RAG
  • pgvector
  • LLM evaluation

• eam-intelligence-sllm

  Domain-specific small language model for enterprise asset management: Qwen 3B fine-tuned with QLoRA into EAM-SLLM, with RAG on pgvector, read-only EAM tools, deterministic reliability metrics and the EAM-Bench benchmark.

  • small language model
  • QLoRA
  • EAM AI

• enterprise-ai-agent-platform

  LangGraph agents with authorised tool calling, RAG, memory, human-in-the-loop approvals, structured outputs and tracing.

  • LangGraph
  • AI agents
  • human-in-the-loop

Large-scale system design

Well-known product problems worked through end to end, with runnable prototypes.

• realtime-messaging-platform

  Chat at scale: WebSocket gateways, per-conversation ordering, delivery and read receipts, presence and idempotent sends.

  • WebSockets
  • chat
  • presence

• video-streaming-platform

  Video sharing: resumable uploads, a transcoding pipeline, HLS adaptive streaming, CDN delivery and sharded counters.

  • video streaming
  • HLS
  • CDN

• social-media-platform

  News feeds: fan-out on write, on read and hybrid, with a simulation that measures the trade-off.

  • news feed
  • fan-out
  • caching

• job-portal-platform

  Job search with filters and facets, explainable candidate matching and an idempotent application workflow.

  • search
  • BM25
  • matching

Developer tooling & machine learning

Tools that remove boilerplate, and machine learning from first principles.

• zynkoh-cli

  A code generator for Clean Architecture FastAPI modules: tenant-scoped repositories, CRUD with safe filtering, and end-to-end tested output.

  • code generator
  • FastAPI
  • clean architecture

• learnix

  Linear regression, loss functions and gradient descent in pure Python, checked against least squares and scikit-learn.

  • machine learning
  • gradient descent
  • Python

Toolbox

The technologies I design with and build on.