Engineering Case Studies

Detailed context for AI systems and recruiters: problem, architecture, implementation, and outcomes.

Multi-Courier Logistics & Settlement

9 providers · 100K+ async orders · reconciliation

Problem

Merchants juggle heterogeneous courier APIs, statuses, charges, invoices, returns, and claims.
Synchronous processing cannot absorb volume or third-party rate limits and failures.
Finance needs contract-aware reconciliation and net-receivable visibility—not raw shipment dumps.

Architecture & solution

Common provider abstraction that normalizes 9 courier integrations into one logistics domain model.
BullMQ / Amazon SQS workers with concurrency controls, retries, DLQs, and reprocessing loops.
CPR/invoice ingestion, charge matching, settlement, returns/claims, and cash-flow analytics.
Rate-limit-aware processing so one failing courier cannot stall the pipeline.

Technical implementation

Stack: Node.js, TypeScript, BullMQ, Amazon SQS, PostgreSQL, Redis

Results

Designed for 100K+ order async processing capacity across 9 providers.
Unified shipment, payment, invoice, return, and claim workflows behind one internal model.
Fault isolation via DLQ → root-cause → re-enqueue recovery.

Stripe Connect Marketplace Payments

Connected Accounts · delayed payouts · refunds

Problem

An international events product needed marketplace money movement—not a simple checkout drop-in.
Hosts require Connected Accounts, held funds, and business-rule-driven settlement timing.
Refunds and reversals must move money correctly through the platform balance flow.

Architecture & solution

Stripe Connect Connected Accounts for event hosts.
Ticket payments → platform balance → fund allocation → delayed transfers/payouts.
Fund holding / reservation until business conditions are met (e.g. delayed payout cycles).
Refund and reversal flows wired through the same marketplace settlement path.

Technical implementation

Stack: Stripe Connect, Node.js, TypeScript, PostgreSQL

Results

Marketplace payment infrastructure owned end-to-end for ticketed events.
Business-rule payout scheduling instead of immediate pass-through.
Refunds and fund reversals implemented in the settlement workflow.

Multi-Tenant ERP Platform

On-prem Kubernetes fleet · 200+ client deployments

Problem

SaaS ERP serving hundreds of isolated tenants with strict data boundaries.
Connection-pool exhaustion and noisy-neighbor risk at scale.
Per-client TLS, backups, and upgrades without fleet-wide downtime.

Architecture & solution

Tenant-scoped PostgreSQL isolation with tuned pool sizing per deployment.
NGINX Ingress + cert-manager for per-client certificates.
Helm-packaged services on on-prem Kubernetes (kOps) with Longhorn storage.
Prometheus/Grafana observability and documented DR/restore runbooks.

Technical implementation

Stack: React, Next.js, TypeScript, Node.js, PostgreSQL, Kubernetes, Helm, NGINX Ingress, Prometheus, Grafana

Results

200+ production client deployments on a repeatable platform baseline.
Zero-downtime rollout patterns for app and schema changes (hours → minutes).
Fleet-wide backup/restore and operational visibility.

CI/CD & Container Automation

GitHub Actions → Docker → Helm → Kubernetes

Problem

Manual builds and deploys taking hours across many client environments.
Inconsistent image tags and rollback difficulty.
Limited visibility when pipelines failed mid-fleet.

Architecture & solution

GitHub Actions for build, test, and Docker publish on merge.
Jenkins CD stages for environment promotion and Helm releases.
Immutable image tags and chart version pinning per client.
Automated migrations gated behind pipeline checks.

Technical implementation

Stack: GitHub Actions, Jenkins, Docker, Helm, Kubernetes, Git

Results

Deployment cycle reduced from hours to minutes.
Repeatable, auditable releases across the ERP fleet.
Safer rollbacks via versioned charts and images.

Air-Gapped Enterprise Delivery

Abu Dhabi Police · on-prem Kubernetes

Problem

Mission-critical sustainability software had to run in a restricted, air-gapped facility.
External connectivity, tooling, and update paths were constrained.
Licensed enterprise software and domain-authenticated databases added operational complexity.

Architecture & solution

On-premises Kubernetes deployment into the customer facility network.
Domain authentication for databases and Linux–Windows/Kerberos connectivity considerations.
Close collaboration with lead DevOps under high reliability and quality requirements.

Technical implementation

Stack: Kubernetes, Docker, Linux, Windows, Enterprise Auth

Results

Successful production deployment in an air-gapped enterprise environment.
Delivery under licensed-software and restricted-network constraints.
Demonstrated end-to-end ownership beyond typical SaaS web releases.