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Szymon Kaczorowski

4.9

(31 reviews)

US$25.00

For every 15 mins

117

Sessions/Jobs

ABOUT ME

Java Tech Lead

Java Tech Lead

I am an experienced Java Tech Lead/Software Engineer with experience in back end and full stack applications.
I'm great in upgrading quality of code, writing fast and testable solutions, keeping big picture in head while still having eye for details.

Polish, English

Warsaw (+01:00)

Joined October 2017

EXPERTISE

10 years experience | 8 endorsements

Experienced Java Developer and Team Lead working with very big systems with experience in multiple domains starting from Telecommunicatio...

Experienced Java Developer and Team Lead working with very big systems with experience in multiple domains starting from Telecommunication, Finance, Gaming, Created multiple efficient systems

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9 years experience

10 years experience

10 years experience | 1 endorsement

5 years experience

REVIEWS FROM CLIENTS

4.9

(31 reviews)

Akamboj00

February 2023

Szymon has now helped me twice, and I would highly recommend to work with him.

Akamboj00

February 2023

Amazing help. Got straight to the point and solved my issue very quickly with great explanations.

Terry Naber

March 2021

Brilliant, young mind! Handled a tricky Artificial Intelligence project and debugged it within an hour! That is something no one else could do in 4 days! Thank you, Szymon!

Removed User

May 2020

Highly talented, solved the issues very quickly and also explained the design and approach.

Xavier Reigneau

March 2020

Szymon helped me on a java project I was having difficulty with. He is fluent in English making the tutoring help worth while.

Testdome

September 2019

Szymon is very knowledgeable about Java Spring.

decsjr

March 2019

Great help with a very complex java assignment.

Steven Kennedy

December 2017

He was a great help! 10/10 would hire again.

Yiu Kitman

December 2017

explain quite good

Pieter Sheth-Voss

December 2017

Szymon is clearly very experienced with software dev/ops. He quickly understood our goals, and showed us a much better way to set up our project. Our task was accomplished in one brief productive worksession.

EMPLOYMENTS

Principal Software Engineer

Grupa VII

2015-03-01-Present

Consulting practice embedded with teams from early-stage startups through scale-ups to global enterprises. Full

lifecycle owners...

Consulting practice embedded with teams from early-stage startups through scale-ups to global enterprises. Full

lifecycle ownership: architecture, development, deployment, production. Clients across fintech, banking, payments,

and travel.

Key Achievements:

• Engineered payment gateway microservices achieving 99.99%+ uptime across multi-region deployments

• Redesigned system architecture supporting 10x scale growth for fintech clients

• Architected AI-powered employee companion integrating LLM models with enterprise workflows

• Built global airline reservations service with enterprise-grade security for PII and payment data

• Built real-time trading platform with streaming data and monitoring, improving client retention

• Led cloud migrations reducing infrastructure costs while improving reliability and scalability

• Drove engineering modernization: trunk-based development, TDD, and CI/CD pipelines

• Executed legacy system migrations using Strangler Fig pattern, minimizing business disruption

• Led engineering teams to become highest-performing units; managed cross-functional teams across timezones

• Built technical knowledge bases and mentorship programs adopted across multiple business units

Java

Node.js

MongoDB

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Java

Node.js

MongoDB

Angular

PostgreSQL

TypeScript

React

Google Cloud Platform

Spring Boot

Kotlin

GraphQL

RESTful API

AWS

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Senior Software Engineer

Rooam

2018-12-01-2020-03-01

*Developing backend and frontend components for multiple services including: point of sale, location services, payment services, user man...

*Developing backend and frontend components for multiple services including: point of sale, location services, payment services, user management. *Improving tech stack and training developers in new technologies, and processes

MongoDB

Groovy

RabbitMQ

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MongoDB

Groovy

RabbitMQ

React

Spring Boot

Kotlin

DigitalOcean

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Tech Lead

Symphony Solutions

2018-03-01-2018-10-01

*Working on features, and improving code style, quality and usage of design patterns for promotions project. *Setting up of correct archi...

*Working on features, and improving code style, quality and usage of design patterns for promotions project. *Setting up of correct architecture of application. *Analysing security. *Mentoring developers. *Performing technical recruitments. *Preparing and giving talks inside and outside of company. *Leading a full stack team of 8 people.

Java

Spring

API

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Java

Spring

API

Cassandra

React

Spring Boot

JavaScript

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