ibrahim kaya

Impact · Nov 2022 – October 2026

The work, in numbers

Everything here comes from my own pull requests, tickets and wiki pages at Migros One (via StartupHeroes). Internal system names, clients and colleagues are left out on purpose; the numbers are mine.

01 · Shift

From building to multiplying

I still ship every week, but most of my leverage now comes from reviewing and unblocking other engineers.

My merged PRsPRs I reviewed for others
020040060013232022Nov–Dec×1.81252652023×2.11675212024×3.11476352025×4.31315022026to Oct×3.8
Bottom row: reviews per merged PR. Since 2024 I review three to four PRs for every one I merge.

02 · Toolbox

What I build with

A quick-commerce delivery domain with millions of orders a month and thousands of couriers on the road.

Language & frameworks

Services, APIs and BFFs

JavaSpring BootJPA / HibernateRxJava

Messaging & events

Event-driven flows that survive bad events

Kafkaretry & dead-letter topicsKafka state storesAvroRabbitMQCDC

Data

Transactional data, caches and search

MySQLRedisCassandraElasticsearchmemcached

Platform

Running and scaling services

AWSKubernetesHPAGitHub ActionsAirflow

Observability & testing

Knowing what production does

PrometheusGrafanaDatadogJMeterJUnit 5

Ways of working

Decisions others can follow

RFCs & ADRsincident postmortemscode reviewmentoring

03 · Focus

Where the effort went

  • Courier app & ops back-office features
  • Courier assignment engine
  • Observability, performance, resilience
  • Event-driven order processing & DLT
  • Multi-tenant platform for external clients
  • Platform & engineering productivity
  • Support & data fixes
  • Runtime configuration platform
  • Mid-mile operations service
  • ETA & new delivery verticals
  • External provider integration
  • Location alerting
  • Route optimisation as a shared service
  • Documentation & analysis
  • Area-related service
Tickets I developed, by theme. Bar length shows the relative share.

04 · Team

Reach beyond my own tickets

1,946

pull requests I reviewed, across 15 repositories

1,736

inline review comments

234

tickets I wrote for teammates

05 · Writing

Decisions on paper

RFCs before big changes, ADRs after them, and an incident report whenever production surprised us.

38pages written on the engineering wiki · 2023–2026
  • Architecture & flows12
  • Team guides8
  • Integration docs5
  • Incident reports5
  • RFCs / ADRs4
  • Analyses4

06 · Flow

How work moves

6.4 h

median time from opening a PR to merge

1,537

pull requests approved after review

46%

of my 880+ ticket comments went to work owned by others