Yalın E.

Real money iGaming platform on Java/Spring Boot microservices: 10–12M game rounds and 18–23M transaction writes a day.

• Wallet transaction p99 latency fell 66% (147.6 to 49.3 ms) and p95 44% over five months; at the peak, with weekly volume up 74%, p99 held at 59.5 ms. My own query consolidation, measured separately: player lookups per transaction down 99%, session queries down 62%.
• Built direct seamless wallet integrations with two major game providers (one carrying 113M rounds in its first full month): idempotent debit, credit and rollback handling, and terminal error codes that ended provider retry loops.
• Led partition pruning on a 10 billion row PostgreSQL transaction table: the worst hot path scan fell from 156 to 4 partitions (10.5 to 1.8 ms). Designed a dedicated idempotency table (0.086 ms average lookup at 20M a day) and a tombstone table for orphan cancels.
• Delivered regulatory automatic withdrawal (120 minute payout rule) in 4 repos before its 1 January 2025 deadline, with negative balance protection and exactly once wallet concurrency tests.
• Found 25–32k game launches a day failing behind HTTP 200, invisible to 5xx monitoring, and drove them to zero. Fixed a provider refund defect that left 2,421 players' rounds open.
• Delivered the first versions of 3 Java/Spring Boot services: live game statistics on Kafka, an operations back office, and a B2B jackpot proxy (the last in about 3 weeks).
• Cut Snyk findings 46% in 6 services; delivered API hardening in 5 repos after a Cloudflare API Shield review.
• Built post deploy verification: 9 Coralogix alerts and automated checks at 15 and 30 minutes; cut the Playwright staging smoke gate from 10m32s to 3m30s; added an 83% JaCoCo gate.
• Authored 3 architecture proposals; the game rounds read model shipped behind a feature flag.

The UCS was developed for the requirements of automated warehouses. It is a vendor-neutral solution that orchestrates automated and human workflows across the warehouse, optimizes order fulfillment end-to-end, and increases productivity. UCS integrates WMS and AMR(Autonomous Mobile Robots) to fulfill needs and creates an environment open for extension. UCS is the first microservice-based application of the company.

• Worked as a full-stack developer in Unified Control System(UCS), mainly focused on the backend. Designed fault-tolerant microservice architecture by creating more than 15 microservices by utilizing RabbitMq message handling.
• Created database per service for every 15+ microservices to ensure scalability of individual microservices.
• Conducted integration and unit testing, including our inner house emulator testing, to ensure the reliability and functionality of the UCS platform with the aim of 80% coverage.
• Performed a load test that can handle 50,000 shipments daily for a warehouse.
• Integrated Geek+ robots into the UCS system to extend and adjust their functionalities into UCS business logic for handling a warehouse with 20 workstations for picking and replenishing shipments.
• Implemented front-end development using Flex Pages and TypeScript, leveraging an in-house front-end framework for the UCS platform.
• Created pipelines using Azure DevOps, managed Maven Artifactory, and implemented Liquibase for database schema management, and Datasync for persisting system data into the database.
• Helped interns and new employees with onboarding and helped them debug and troubleshoot, increasing their sprint speed by 20%.
• Used MirrorD, Konga, and Openlens for Kubernetes development environment.

GeoSolutions är specialiserade i processen och spridningen av raster och vector geospatial data med Open Source-mjukvara enligt de standarder som skapades av Open GeoSpatial Consortium (OGC) och ISO Technical Committee 211, vilka levererar basen till INSPIRE förordningarna.

• Deltog i open source geographic information system (GIS)-projektet, från företaget GeoServer and GeoTools.
• Utvecklade och underhöll open-source projekt enligt de olika klienters behov genom att erbjuda konsultering.
• Adderade modular extensions enligt klientens behov. Återskapade deras errors och levererade snabbare lösningar.
• Arbetade med CI/CD pipeline, implementerade enhet- och integrationstest för alla nya funktionaliteter.

Nokia Corporation är ett Finskt multinationellt informationsteknologiskt, kundelektroniskt telekomföretag, grundat 1865.

• Utvecklade ett webbinventory spårningssystem till en av Turkiets största ISP:er, vilket har fler än 50 miljoner användare.
• Förbättrade systemprestandan och omprogrammerade koden.
• Nästan 500.000 dagliga API requests reducerades till 10
• Gjorde koden mer robust och beroendet mellan moduler minskades
• Ökade den automatiserade kapaciteten av systemet och reducerade 6 dagars arbete månadsvis till 5 minuter.
• Implementerade nya moduler användandes av Test Driven Development (TDD).
• Skrev enhetstest till äldre klasser som har en kritisk del i systemet.

AYESAŞ, som en av de ledande lösningsleverantörerna inom den Turkiska Försvarsindustrin, opererande i Aerospace och Försvar och har tillhandahållit avancerade lösningar i business-områden som C4ISR, Avionics, Electronic- och Electromechanical-system

• Bidrog till den Turkiska Regeringens första helikopterprojekt och första distrubition av arkitekterad UAV uppdragsplannerings-mjukvara
• Utvecklade med hjälp av Test Driven Development och nådde åtminstone 80% täckning på klasser.
• Utvecklade microtjänster användandes gRPC vilket gjorde det möjligt med bi-directional streaming mellan användare och applikation, samtidigt som det krypterades och samlade in data i små paket.