Marcin Cieślak, Developer in Warsaw, Poland
Marcin is available for hire
Hire Marcin

Marcin Cieślak

Verified Expert  in Engineering

Back-end Developer

Warsaw, Poland
Toptal Member Since
September 14, 2022

Marcin is a valued full-stack developer with 15 years of experience. He has a leading role in an e-learning project, which delivers over one million lessons yearly to universities around the globe. He is also an efficient and respected tutor, facilitator, and teaching materials writer. Marcin is a resourceful team player, not afraid of taking on a wide range of responsibilities while staying highly focused on the result.


Coders Lab
Java, University Teaching, SQL, Jakarta Server Pages (JSP), Algorithms, Spring...
Ct Lams International
Java 11, Spring, Hibernate, JavaScript, Jakarta Server Pages (JSP), JPA...
Java, MySQL, SNMP, Cisco, Microservices, Hibernate, HTML5, HTML, CSS, Java 8




Preferred Environment

Windows, Java 11, MySQL, Hibernate, Spring, JavaScript, JPA, jQuery, SVG, Jakarta Server Pages (JSP)

The most amazing...

...thing I've done is keeping a large international e-learning platform thriving for years with minimal staff.

Work Experience

Teacher | Mentor

2018 - PRESENT
Coders Lab
  • Conducted face-to-face and online lessons for over 200 bootcamp students.
  • Mentored groups of six to 16 students in each course.
  • Provided lessons and materials about Java, Spring MVC, Spring Boot, Hibernate, SQL, JSP, and JavaScript to the students.
  • Was considered the best and friendliest teacher in most courses.
Technologies: Java, University Teaching, SQL, Jakarta Server Pages (JSP), Algorithms, Spring, Hibernate, Apache Tomcat, Java 8

Senior Full-stack Developer

2008 - PRESENT
Ct Lams International
  • Made vital decisions about the project's architecture and roadmap.
  • Delivered over one million lessons per year to universities around the globe.
  • Maintained the project with a very small team for over a decade.
  • Conducted training for universities adopting the project.
  • Performed planned and ad-hoc deployment to test and production sites.
  • Headed sub-teams of several developers and interns.
Technologies: Java 11, Spring, Hibernate, JavaScript, Jakarta Server Pages (JSP), JPA, WildFly, MySQL, Git, Learning Tools Interoperability (LTI), HTML5, CSS, Software Project Management, HTML, Full-stack, D3.js, IT Project Management, Apache Tomcat, Java 8

Full-stack Developer

2009 - 2011
  • Managed a team of six developers to deliver a telco monitoring project.
  • Contributed to a high-load project aimed at throttling data usage by telco users.
  • Reverse-engineered and supported a captive portal for a chain of hotels.
Technologies: Java, MySQL, SNMP, Cisco, Microservices, Hibernate, HTML5, HTML, CSS, Java 8

LAMS Platform
An e-learning platform for universities to facilitate face-to-face and online teaching. It enables applying various pedagogical approaches by providing a comprehensive set of learning tools like assessments, forums, chats, and task lists. Also, it allows complex flow, like stopping students at gates, optional activities, and time limits. The project is used by tens of thousands of global users, most notably in Singapore and the UK.

I have been a member of the project most of my professional life after I started working on it as an intern. I am now the sole architect and developer.
2010 - 2011

Coursework in Management

Warsaw School of Economics - Warsaw, Poland

2002 - 2007

Master of Science Degree in Software Engineering

Wroclaw University of Science and Technology - Wroclaw, Poland


Project Management Certification

Warsaw School of Economics


jQuery, D3.js


WildFly, Apache Tomcat, Slack, Git


Java, HTML, Java 8, Java 11, JavaScript, SQL, CSS, HTML5


Spring, Hibernate, JPA, Jakarta Server Pages (JSP)




MySQL, PostgreSQL


Microservices, Management


Software Development, Full-stack, IT Project Management, Learning Tools Interoperability (LTI), Algorithms, Software Project Management, APIs, API Integration, Integration, SVG, University Teaching, SNMP, Cisco, Team Leadership, Critical Path Analysis, Employees, Back-end

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.


Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring