BHY / CAREER RUNInteractive portfolio

ENGINEERING / PAYMENTS / LEADERSHIP

Bahadır Halil Yalçın

Senior Software Engineer & Team Lead / Payment Systems

Senior Software Engineer and Team Lead at Firisbe, combining hands-on full-stack development with engineering team management. Focused on payment infrastructure, merchant onboarding, digital wallets, and reliable product delivery.

Firisbe'de ödeme sistemleri, üye iş yeri edinimi ve dijital cüzdanlar üzerine çalışan kıdemli yazılım mühendisi ve ekip lideri.

Professional experience

2023-Present / work

Firisbe - Senior Software Engineer & Team Lead / Payment Systems

  • Lead the engineering team, coordinate delivery priorities, review code, and mentor developers while contributing hands-on to product development
  • Build payment services, merchant portals, operational dashboards, and mobile flows within Firisbe's payment and digital wallet ecosystem
  • Develop and improve end-to-end payment flows, including API integration, virtual POS selection, installments, 3D Secure callbacks, and transaction state handling
  • Implement merchant onboarding and document workflows, including agreement acceptance, revision uploads, and consistent frontend and backend state
  • Develop QA automation and internal tools to test payment scenarios, investigate errors, and improve release confidence
  • Work across React, Next.js, Node.js, Java, PostgreSQL, MongoDB, and Kafka, with attention to maintainability and secure API design

Internship experience

HAVELSAN - Internship

ARD Grup - Internship

Skills & technologies

Selected projects & education

2011-2013 / project

Founder Project: SpecialWar

  • Built and operated SpecialWar, an MMO FPS hobby project, from gameplay systems to backend services
  • Developed multiplayer mechanics, account flows, admin tooling, and MySQL-backed services with C++
  • Managed releases, player feedback, moderation needs, performance issues, and infrastructure decisions
  • Implemented early anti-cheat and real-time gameplay patterns while learning product ownership hands-on

2013-2018 / education

Selçuk University

  • B.Sc. Computer Engineering
  • Built foundations in algorithms, data structures, databases, networking, and software architecture
  • Completed academic software projects across web, backend, and distributed-system concepts
  • Developed practical discipline in debugging, documentation, teamwork, and technical problem solving

2016-2019 / project

Early Product Engineering Practice

  • Built full-stack web applications and prototypes while studying, focusing on practical product delivery
  • Used ASP.NET MVC, JavaScript, SQL, REST APIs, and admin-panel patterns across academic and personal projects
  • Practiced requirements analysis, database modeling, authentication flows, and deployable interfaces
  • Turned early project work into a foundation for later fintech and enterprise engineering

2019-2022 / education

Chang'an University - Master's Degree

  • M.Sc. Software Engineering (China Government Scholarship recipient)
  • Research in cloud computing, microservices architecture & AI applications
  • International academic work with English-language collaboration and technical writing
  • Built a wider systems perspective that later shaped payment infrastructure work

2021-2023 / project

Independent Full-Stack & Fintech Preparation

  • Built and studied production-style backend services, dashboards, and integration patterns before joining Firisbe
  • Strengthened .NET, Node.js, React, relational databases, Docker, messaging, and API design through hands-on projects
  • Focused on reliability patterns such as audit trails, error handling, observability, CI/CD basics, and data consistency
  • Moved from general full-stack work toward payment-domain engineering and regulated fintech constraints