Curriculum vitae

Ibrahim Kaya

Senior Backend Engineer · Tech Lead

İzmir, Türkiye · open to remote · 96ibrahimkaya@gmail.com

StartupHeroes — consultant at Migros One · remote

Nov 2022 – now

Tech Lead Jan 2025 – now · Software Engineer Nov 2022 – Feb 2025

Fast Delivery & Delivery domain: millions of orders a month, thousands of couriers. 583 merged PRs across 25 repositories.

Built 3 services end to end and helped shape 5 in total, from the initial idea through design to architecture decisions.
Founded an area-related domain service and decoupled area data from 4 services using CDC-based active replication, read-only APIs and a config-gated migration of write ownership.
Turned the in-house delivery platform into a multi-tenant platform for external clients: multi-tenant company/vertical authorization, an internal order flow independent of the core order system, JWT and IP-based auth, plus two new services.
Turned the route optimisation engine into a shared service for other teams, with asynchronous job processing and scaling work.
Wrote the core of the mid-mile operations service moving goods from warehouses to micro-hubs; authored the technical analysis and the epic’s 23 sub-tasks.
Delivered an external provider integration end to end in about four months.

Owned the courier auto-assignment engine: optimiser integration, region saturation, persistent route history; fixed manual vs. automatic assignment race conditions with region locks; rolled out event-based assignment to all regions.
Built a runtime configuration platform that lets operations tune assignment and ETA behaviour without deployments.
Real-time courier observability: 1,000–1,500 location events per second, anomaly detection and alerts; moved location alarms into a dedicated service with hexagon-based geofencing.
Built the BFFs for the courier mobile app and the operations back-office, including a rule engine for manual assignment.

Moved order processing from a synchronous legacy dependency to event-driven Kafka flows (fat events, Avro, feature-flagged topic migration).
Introduced dead-letter topics, non-blocking retry and manual retry tooling for critical consumers, bringing order loss and major event-processing incidents down to near zero.
Eliminated deploy-time timeouts by aligning load balancer deregistration with graceful shutdown; tuned health checks so 30-minute jobs survive rolling updates.
Platform modernisation: test framework, Java and internal framework migrations; scheduled jobs moved to Airflow.

Lead 3 backend engineers and 2 QA; 1:1s, quarterly performance reviews, hiring interviews, onboarding.
1,946 PR reviews (1,537 approvals, 1,700+ inline comments) across 15 repositories.
Supported other engineers beyond my own scope; wrote and distributed 234 tickets across the team.
Authored 38 engineering documents: 4 RFCs/ADRs, 5 incident reports, 8 team guides.

Dec 2021 – Nov 2022

Wrote a service end to end in a Kafka-based pipeline that let AI models process images more efficiently for an AI image-recognition security product.
Java, Spring Boot, Kafka, Redis.

Oct 2020 – Nov 2021

Languages & frameworks: Java, Spring Boot, JPA, RxJava
Messaging & data: Kafka (DLT, retry, state stores), MySQL, Redis
Infrastructure & observability: Kubernetes, Prometheus, Grafana, Datadog, JMeter
Practices: Microservices, event-driven architecture, multi-tenancy, BFF, RFC/ADR writing, incident postmortems, code review, mentoring

B.Sc. Computer Engineering — İstanbul University · 2020

Turkish (native) · English (professional working proficiency)