Khalil Alyacoubi

Backend Engineer | Full-Stack Development

Profile summary

Key skills

Professional experience

• •Re-architected the order path to acknowledge API requests at 11ms p95 by validating, reserving stock in Redis, and enqueuing tasks, replacing a synchronous process that previously took 5s p95 and 24s worst case. Maintained order success rates across 108k requests with zero 5xx errors.
• •Prevented inventory loss and overselling by implementing atomic Redis DECR operations with compensating rollbacks and conditional UPDATE guards, eliminating the need for distributed locks while maintaining database stock invariants.
• •Secured payment outcomes by flagging orders for reconciliation when charge status is uncertain, and resolved defects in idempotency, stock counting, and payment-failure handling identified during an audit of the original implementation.

• •Facilitated Advanced Python Programming labs for 400+ students by translating algorithmic concepts into practical exercises.
• •Mentored students on coding tasks, emphasizing problem-solving, debugging, and clean code practices.
• •Evaluated Python implementations, providing feedback on correctness, code quality, and algorithmic thinking.

• •Designed an adaptive dashboard using a weighted behavioral-scoring engine with per-event weights and repetition caps: the UI reorders based on user behavior to surface frequent workflows automatically. This approach allows a 300-module product to adapt to the user.
• •Led front-end architecture, including a multi-language content schema that supports new languages without migrations, and implemented motion work achieving 95 Performance, 100 Accessibility, and 100 SEO scores on Lighthouse.
• •Built the platform's real-time core by developing a WebSocket notification layer from scratch.
• •Managed CI/CD via GitHub Actions, including automated linting, builds, and testing with auto-issue creation on failure, and coordinated delivery across the engineering pair.

• •Load-tested the booking write path, identifying an 80% failure rate under concurrent load; rebuilt the system to achieve 0% timeouts and a 6.4x increase in throughput (from 9 to 58 req/s) using per-employee mutexes, READ COMMITTED isolation, minimized critical sections, and deadlock retries.
• •Built a constraint-based scheduling engine to compute real-time availability across staff shifts, breaks, and multi-service appointments, securing slot integrity with stateless HMAC-signed tokens to prevent tampering.
• •Shipped the platform end-to-end, including JWT and OTP authentication for 4 roles, policy-driven field-level RBAC, Salla webhook integration, and SSE order tracking across 81 REST endpoints and a 17-table relational schema.
• •Diagnosed customer drop-off in the booking flow and rebuilt the front end to include instant service search, a streamlined booking path, and a consolidated searchable field for the 5-level service selector.

Education

Completed a degree in Multimedia and Web Development, focusing on full-stack engineering, UI/UX, system analysis, and performance-oriented development. Graduated with an 89.08% overall score and ranked 2nd in the cohort.

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