enrinal

Muhamad Enrinal Zulhimar

Senior Backend Engineer

Summary

Senior backend engineer with 8+ years of experience building booking and payment systems in Go and Java. At Tiket.com I own the core flight booking services, which handle over 100,000 bookings a day, and I work closely with the Hotel and Promo teams on cross-vertical projects.

Experience

Tiket.com

Jakarta, Indonesia
Senior Backend Engineer IIJul 2026 – Present
  • Architected server-side cart lifecycle management for flight checkout, with abandoned-cart re-engagement, exactly-once push notifications, and one-tap recovery of expired carts. Built on Spring WebFlux, Redis, and Kafka.
  • Designed idempotent booking with a distributed lock and request coalescing to fix a race condition that could book the same order twice with the airline. Retries across all 7 booking API versions now return the original booking.
  • Root-caused and fixed an off-heap Netty memory leak that crashed every flight-cart pod about 12 times a month.
  • Built booking health monitoring for the flight platform, with Grafana dashboards and alerts for drops in supplier booking success, spikes in business errors, and falls in order creation. Added cache hit-rate and Kafka consumer lag metrics across 4 services.
  • Lead system design reviews, on-call, and incident post-mortems for a team of 5 engineers, and drive cross-vertical projects with the Hotel and Promo teams.
Senior Software Engineer, BackendAug 2022 – Jul 2026
  • Led the consolidation of fragmented MongoDB databases into a single cluster and redesigned the data model to eliminate cross-database joins, cutting p99 latency by 40% and database cost by about 30%; later adopted by other verticals.
  • Cut Redis memory by about 75% with Brotli payload compression and jittered TTLs that prevent cache stampedes at peak traffic; later adopted by other verticals.
  • Led the Flight + Hotel package booking, a cross-vertical project spanning two independent booking systems. Built a saga orchestrator in Go with compensating transactions, eliminating charged-but-unbooked orders.
  • Built a rule-based pricing engine for add-ons that lets product teams launch pricing changes without a deployment, lifting upsell conversion by about 13%.

SiCepat Express

Jakarta, Indonesia
Software Engineer, BackendJul 2021 – Jul 2022
  • Built idempotent event processing for shipment tracking on Kafka and Redis, so no event is lost or applied twice, improving shipment status accuracy by about 25%.
  • Built an OCR pipeline to verify merchant ID cards automatically, cutting merchant onboarding time by about 50%.

Warung Pintar

Jakarta, Indonesia
Software Engineer, BackendJan 2020 – Jul 2021
  • Built the event-driven backend for the merchant sales platform, which scaled without a redesign as GMV grew 60%.
  • Built Kafka-based notification and wallet services processing over 100,000 messages a day.

Angsur

Bandar Lampung, Indonesia
Software EngineerJan 2018 – Oct 2019
  • Built REST APIs and internal tools for credit underwriting, reducing credit validation time by about 30%.

Teaching

Ruangguru

Jakarta, Indonesia
Backend Engineering Instructor, part-timeFeb 2022 – Jul 2024

Designed a backend course on Go, system design, and production operations, and mentored 5 university cohorts.

Skills

Languages
Go, Java (Spring WebFlux, Project Reactor), Python, SQL
Data and messaging
MongoDB, PostgreSQL, Redis, Elasticsearch, Kafka, NATS
Infrastructure
GCP, Kubernetes, Docker, gRPC, GraphQL, distributed tracing, SLO alerting

Education

Degree
B.Eng. Informatics Engineering, Institut Teknologi Sumatera, 2020, Cum Laude (GPA 3.66/4.00)
Awards
ICPC Asia Jakarta Regional finalist, ranked 21st