Sebastian Drag - Senior Software Engineer

Q: Where is Sebastian based?

Sebastian is based in Katowice, Poland .

Q: What languages does Sebastian speak?

Sebastian speaks the following languages: English (Advanced), Polish (Elementary) .

Q: How many years of experience does Sebastian have?

Sebastian has at least 6 years of experience. During this time, Sebastian has worked in at least 2 different roles and for 3 different companies . The average length of individual experience is 2 years . Note that Sebastian may not have shared all experience and actually has more experience.

Q: What is Sebastian's latest experience?

Sebastian's most recent position is Senior Software Engineer at Visa .

Q: What companies has Sebastian worked for in recent years?

In recent years, Sebastian has worked for Visa and eBay .

Q: Which industries is Sebastian most experienced in?

Sebastian is most experienced in industries like Information Technology , Banking and Finance , and Retail . Sebastian also has some experience in Healthcare .

Q: Which business areas is Sebastian most experienced in?

Sebastian is most experienced in business areas like Information Technology , Quality Assurance , and Operations .

Q: Which industries has Sebastian worked in recently?

Sebastian has recently worked in industries like Information Technology , Banking and Finance , and Retail .

Q: Which business areas has Sebastian worked in recently?

Sebastian has recently worked in business areas like Information Technology , Quality Assurance , and Operations .

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Katowice, Poland

Check rate

Experience

Sep 2023 - Present

2 years 11 months

Senior Software Engineer

Visa

Built Python-based release checks for payment settlement workflows, helping teams validate configuration, version control history, and deployment readiness before changes reached card-processing environments.
Implemented Azure DevOps pipelines for reconciliation jobs and service rollouts, reducing manual release steps and cutting failed deployments by 30% across several regional environments.
Designed YAML automation for environment provisioning and parameterized builds, which gave operations teams a repeatable way to promote fixes between test and pre-production systems.
Refined monitoring scripts that compared transaction files, queue backlogs, and batch outputs, making it easier to catch missing records before daily settlement windows closed.
Partnered with engineers on Git branching and merge checks for shared payment services, helping standardize how hotfixes and scheduled releases moved through review.
Wrote Python utilities to validate card network message payloads and export audit-ready summaries, which improved troubleshooting during payment exception investigations.
Prepared runbooks and deployment notes for support teams so release handoffs were clearer during incident response and after-hours maintenance windows.
Supported CI troubleshooting for containerized services and build agents, keeping critical payment workflows available during frequent compliance-driven updates.

Feb 2021 - Aug 2023

2 years 7 months

Software Engineer

eBay

Built automation for seller listing and order-processing services, helping product teams verify release health across checkout, catalog, and marketplace workflow updates.
Implemented CI pipelines for Python services that handled pricing, inventory sync, and seller notifications, which shortened integration feedback loops for engineering teams.
Created reusable YAML templates for build, test, and deploy stages, improving consistency across multiple repositories and reducing pipeline drift.
Developed scripts to validate API responses and data feeds used by search and listing workflows, catching malformed records before they affected customer-facing pages.
Improved Docker-based test environments for developer and QA use, allowing teams to reproduce deployment issues without depending on shared infrastructure.
Added automated checks for rollback readiness and release notes generation, which made production changes easier to review during busy commerce events.
Worked with support and platform engineers to document CI failures and environment fixes, helping reduce repeated incidents tied to branch merges and artifact promotion.

Aug 2020 - Jan 2021

6 months

Software Engineer

Philips

Supported build and release automation for clinical software workflows, including package validation for applications used by hospital and service teams.
Implemented Python scripts that checked device data exports and configuration bundles, helping engineers catch mismatches before software updates reached validation environments.
Configured Jenkins jobs for testing and deployment steps, giving the team a repeatable path for moving fixes through regulated development stages.
Improved Git-based version tracking and release documentation for healthcare applications, making audit reviews easier for both engineering and quality groups.
Wrote lightweight utilities to compare logs, verify installation outputs, and flag environment setup issues, which reduced time spent on manual troubleshooting during releases.

Industry Experience

See where this freelancer has spent most of their professional time.

Experienced in Information Technology, Banking and Finance, Retail, and Healthcare.

Information Technology

Banking and Finance

Retail

Healthcare

Business Area Experience

See which departments and functions this freelancer has contributed to most.

Experienced in Information Technology, Quality Assurance, and Operations.

Information Technology

Quality Assurance

Operations

Summary

Software engineer with experience building release automation, workflow checks, and operational tooling for payment, e-commerce, and healthcare systems. I have worked on teams that needed stable deployments, clear change control, and practical documentation so engineers and stakeholders could ship safely across complex environments.

Skills

Python, Sql, Bash, Yaml
Flask, Fastapi, Pandas, Pytest
Azure Devops, Git, Jenkins, Docker, Kubernetes, Ansible
Azure, Aws (Ec2, S3, Cloudwatch)
Postgresql, Mysql, Redis, Elasticsearch
Kafka, Rabbitmq, Rest Apis, Graphql
Selenium, Postman, Jmeter, Sonarqube

Languages

English

Advanced

Polish

Elementary

Education

Oct 2017 - Jun 2020

University of Silesia

B.S. · Computer Science · Katowice, Poland

Statistics

Experience

Total positions 3

Experience in Information Technology 5.5 y

Avg length 1 y 11 m

Longest experience 2 y 10 m

Expertise

Recent roles Senior Software Engineer, Software Engineer

Main industries Information Technology, Banking and Finance, Retail

Main business areas Information Technology, Quality Assurance, Operations

Qualifications

Highest degree Bachelor

Profile

Created

July 2026

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Frequently asked questions

Have questions? Find more information here.

Where is Sebastian based?

Sebastian is based in Katowice, Poland.

What languages does Sebastian speak?

Sebastian speaks the following languages: English (Advanced), Polish (Elementary).

How many years of experience does Sebastian have?

Sebastian has at least 6 years of experience. During this time, Sebastian has worked in at least 2 different roles and for 3 different companies. The average length of individual experience is 2 years. Note that Sebastian may not have shared all experience and actually has more experience.

What roles would Sebastian be best suited for?

Based on recent experience, Sebastian would be well-suited for roles such as: Senior Software Engineer, Software Engineer.

What is Sebastian's latest experience?

Sebastian's most recent position is Senior Software Engineer at Visa.

What companies has Sebastian worked for in recent years?

In recent years, Sebastian has worked for Visa and eBay.

Which industries is Sebastian most experienced in?

Sebastian is most experienced in industries like Information Technology, Banking and Finance, and Retail. Sebastian also has some experience in Healthcare.

Which business areas is Sebastian most experienced in?

Sebastian is most experienced in business areas like Information Technology, Quality Assurance, and Operations.

Which industries has Sebastian worked in recently?

Sebastian has recently worked in industries like Information Technology, Banking and Finance, and Retail.

Which business areas has Sebastian worked in recently?

Sebastian has recently worked in business areas like Information Technology, Quality Assurance, and Operations.

What is Sebastian's education?

Sebastian holds a Bachelor in Computer Science from University of Silesia.

What is the availability of Sebastian?

Sebastian is immediately available full-time for suitable projects.

What is the rate of Sebastian?

Sebastian's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.