Sk Mastan

Bachelor of Technology in Computer Science and Engineering · CGPA: 9.15/10.0

Diploma in Computer Engineering · CGPA: 9.78/10.0

• Building full-stack features for Clutch, an athlete-coach marketplace: coach discovery, sign-in flows, story text layers, profile photos, and account lifecycle, shipped through reviewed PRs and CI.
• Fixed a pricing-upgrade exploit in the billing flow and helped migrate the app to a monolith, with per-feature merge workflows and automated code-review tooling.

• On Oracle Textura DaaS, built GraphQL validation and query-generation workflows mapping 270+ legacy reporting fields into API contracts, plus schema-introspection assets reused across 22 root APIs and 61 entity types.
• Led performance validation for production-bound GraphQL features, benchmarking 52 nested/subgraph scenarios and request windows up to 10K records to catch timeout, pagination, N+1, and query-complexity regressions.
• Built AI-agent automation for DaaS regression workflows across Jenkins, TestRail, RestAssured, test-data generation, log analysis, and defect triage.

• Developed full-stack React.js/Node.js workflows for internal and customer-facing systems, and managed Linux deployments (SSH access controls, firewall, Bash automation), sustaining 99% uptime.

• Event-driven Node.js backend that verifies Stripe webhook signatures with express.raw() payloads and stripe-signature headers before processing any event.
• Order fulfillment only runs after payment confirmation: a state machine walks checkout.session.completed and payment_intent.succeeded, keeping payment acceptance separate from application logic.

• Spring Boot ledger service for account transfers with idempotency keys, ACID transaction boundaries, strict lock ordering, and optimistic locking to prevent double-spend and race-condition failures.
• Stripe-style retry semantics that return cached responses for duplicate transaction keys, preserving balances across network retries and concurrent transfer attempts.

• Redis-backed sliding-window rate limiting middleware with sorted-set timestamps and atomic TxPipeline operations, enabling shared throttling state across distributed API nodes.
• Gin-based API guard enforcing a 5-request/10-second per-IP policy with deterministic 429 responses after the configured threshold is exceeded.