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About / Experience

Ersel Seyit

Backend & Distributed Systems Engineer

I build and operate complete systems — the infrastructure, the services, and the interfaces people use. My work spans telecom operations, distributed systems, and shipped web and mobile products.

Brussels, BelgiumGitHub (opens in a new tab)LinkedIn (opens in a new tab)
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Selected work

Base Station O&M Platform

A telecom operations platform I built and operated solo. PostGIS spatial indexing took geographic queries over 100,000 records from 8.5 seconds to 5 milliseconds.

Explore the platform
Microservices
10
Tests
605
Kubernetes pods
19

108K lines across five languages: 43K Java, 27K Python, 20K React/TypeScript, 11K Go, 5K C.

Experience

Sep 2025 - Present

Istanbul, Turkey · Self-directed products

Software Engineer

Independent

  • Built, deployed and still run the Base Station O&M platform on Kubernetes, alone. Shipped Feather, a subscription mobile product in Flutter.
  • Built this portfolio in Next.js and TypeScript, with a module registry, interactive demos, a window manager, and architecture deep-dives.
  • Shipped and operate İstanbul Chess on Cloudflare Workers, with per-game state, server-authoritative clocks, and storage-backed reconnect.

Feb 2025 - Aug 2025

Brussels, Belgium

Research Engineer

UpcoMinds

  • Deployed Java/Spring Boot services on a self-managed Kubernetes cluster on AWS EC2 with Amazon RDS (PostgreSQL) for a production AI/ML pipeline
  • Provisioned the cluster with the Fabric8 Java client. Cut model training time by 70% through concurrent processing across nodes.
  • Cut deployment time by 60% with Bitbucket Pipelines and secured APIs with Keycloak OAuth2 and RBAC.

Apr 2024 - Dec 2024

Istanbul, Turkey (Remote)

Software Engineer

Freelance

  • Built a cross-platform medical imaging app in Flutter and Python with custom TensorFlow models: four architectures compared, 93.7% accuracy and 95.4% F1 on a held-out test set
  • Developed financial planning app with Python backend, integrating OpenAI GPT API for natural language budget analysis

Jul 2022 - Feb 2023

Istanbul, Turkey

Software Developer (intern → part-time)

Amani AI

  • Shipped an OpenCV pipeline detecting invalidated Turkish identity documents in 2 weeks against a 2-month estimate, removing manual review from the fraud-check workflow

Technical skills

Languages
Java · Python · Go · C · C++ · Rust · TypeScript · Dart · SQL
Backend & Messaging
Spring Boot · Spring Cloud · Microservices · REST API Design · RabbitMQ
Frontend & Mobile
React 18 · Next.js · TypeScript · WebSockets · Real-time dashboards · Astro · Flutter · Cloudflare Workers · Durable Objects
Cloud & DevOps
AWS (EC2, RDS) · Kubernetes · Docker · CI/CD · Bitbucket Pipelines · GitHub Actions · Helm
Databases
PostgreSQL · PostGIS · MySQL · MongoDB · Redis
Monitoring
Prometheus · Grafana · Zipkin · Loki
Security
Keycloak · OAuth2 · JWT · RBAC
Tools
Git · Linux · Maven · TensorFlow
Testing
JUnit · Mockito · Integration Testing

Education

2020 - 2024

B.Sc. Computer Engineering

Yeditepe University, Istanbul

2018 - 2020

Computer Programming

Ege University, Izmir

Work together

A role, a project, or a system to build.

Available immediately — on-site in Belgium and the Netherlands, or remote for a team anywhere in the world, US and APAC hours included. EU citizen with the full right to work across the EU and EEA, so no sponsorship is required. Open to contract or permanent.

  1. 01

    Share the context

    Send the role or project, the system involved, and the constraints that matter.

  2. 02

    Talk through the work

    We discuss the stack, the team, and where my experience could help.

  3. 03

    Agree the next step

    An interview for a permanent role, or a defined piece of work for a contract.

erselseyit@gmail.com

Know a team looking for this experience? Share erselseyit.com or the CV above. An introduction is welcome.