Piotr Jachowicz, Developer in Warsaw, Poland
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Piotr Jachowicz

Verified Expert  in Engineering

Software Developer

Warsaw, Poland
Toptal Member Since
September 13, 2018

Piotr is a full-stack web developer who started with .NET as his chosen back-end framework and, more recently, worked mainly with Node.js in the front end. He is proficient in React and Vue. Piotr is a quick learner, willing and able to learn new skills rapidly, and is experienced in working in a multinational environment. He has cooperated with teams and clients from various European countries, the US, and Asia.


Node.js, TypeScript, RabbitMQ, React, Express.js, Amazon Web Services (AWS)...
ASP.NET, Web API 2, Vue, SCSS, Agile, SQL, RabbitMQ, Zoho API, CSS, .NET...
Multiple Coding Academies
Windows Communication Framework (WCF), Entity Framework, SQL, jQuery, Angular...




Preferred Environment

Windows, Git, Visual Studio Code (VS Code), Azure

The most amazing...

...project I've worked on was setting up of a system for finding people and leads for a freelance startup.

Work Experience

Full-stack Developer

2022 - PRESENT
  • Worked on creating tools that set up the supply pipeline—finding builders with the skills that clients needed.
  • Created integrations with various APIs, such as Search Engine Results Page (SERP) or SignalHire.
  • Worked on the pipeline efficiency to process files with thousands of lines efficiently and asynchronously, using microservices and 3rd-party services.
  • Developed a front-end internal tooling platform in React to give access to all the tools the team built to the other employees in the company.
Technologies: Node.js, TypeScript, RabbitMQ, React, Express.js, Amazon Web Services (AWS), Kubernetes, CSS, JavaScript, Git, HTML5, Redux

Full-stack Lead Developer

2019 - PRESENT
  • Developed integration with 3rd-party APIs such as DocuSign and Zoho for document collaborative work.
  • Worked on automation tools such as an auto-assignment feature that allowed users to create rules that triggered the automatic filling out of form fields when creating contracts.
  • Introduced Vue to a legacy .NET Web Forms application and modernized the platform to a SPA architecture. Oversaw the process of rewriting logic and views to the new architecture.
  • Developed a new component in Vue that was used to define complex conditions based on field values, used throughout the application in many features.
  • Oversaw the creation of coding standards and started a discussion about code quality management in the company.
Technologies: ASP.NET, Web API 2, Vue, SCSS, Agile, SQL, RabbitMQ, Zoho API, CSS, .NET, JavaScript, C#, Git, HTML5, .NET Core, C#.NET

IT Trainer

2016 - PRESENT
Multiple Coding Academies
  • Designed and conducted multiple workshops for beginner-level developers concerning various full-stack web technologies like Angular 6, .NET Web API, Basics of C#, CSS, SCSS, jQuery, and more.
  • Designed and conducted multiple expert-level workshops for large companies such as the advanced development of WCF services, design patterns and code quality in C#, and advanced JavaScript.
  • Advised on the planned range of training and their scope.
Technologies: Windows Communication Framework (WCF), Entity Framework, SQL, jQuery, Angular, .NET, CSS, JavaScript, C#, Git, HTML5, .NET Core, C#.NET

Senior Vue, Angular, and .NET Developer

2018 - 2021
Santander Denmark (via ProData Consult)
  • Maintained and developed a new functionality on Santander Denmark's main web page and platform.
  • Developed and maintained the front-end layer of Santander Denmark's main page.
  • Built the Santander Finland webpage using React and Episerver.
Technologies: React, .NET, Vue, CSS, JavaScript, C#, Git, Agile, HTML5, ASP.NET Web API, .NET Core, C#.NET

Azure Developer

2018 - 2020
  • Maintained and rewrote the newer version of a mobile app's back end in Node.js.
  • Created a deployment pipeline along with a test environment for the client.
  • Developed modern tooling for the client with the front end in Angular and the back end in Node.js and .NET.
  • Implemented a back end for subscriptions as in-app payments for the Apple Store and Google Play Store.
  • Maintained and developed a Microsft SQL database and an API in Node.js that utilized this database.
  • Refactored a legacy service that processed weather data written in C#.
Technologies: Angular, Node.js, Azure, JavaScript, Git

Full-stack Angular Developer

2019 - 2019
ForagerOne (via Toptal)
  • Developed features on the company's main page and the educational platform.
  • Worked on both the front-end and the back-end layer.
  • Refactored legacy code and improved the performance of the existing solution on the platform.
Technologies: Angular, Node.js, TypeScript, CSS, JavaScript, Git, HTML5

Freelance Angular Developer

2018 - 2019
  • Created a taskboard in Angular according to the design.
  • Built multiple components based on wireframes provided by the design team.
  • Cooperated with the designers and back-end developers to ensure the proper quality of the provided solution.
Technologies: Angular, CSS, JavaScript, Git, HTML5

.NET Web Developer

2017 - 2018
  • Refactored the existing code to use design patterns and best practices.
  • Developed a service in .NET Core to be used for new pricing model calculations.
  • Maintained the largest recruitment platform in the UK.
Technologies: Octopus Deploy, TeamCity, jQuery, Microsoft SQL Server, ASP.NET Core, CSS, .NET, JavaScript, C#, Git, Agile, Scrum, HTML5, ASP.NET Web API, C#.NET

.NET Lead Developer

2017 - 2017
  • Managed the work of a team of four full-stack developers.
  • Mentored the team and enforced Scrum principles, ensuring the Scrum process's quality.
  • Created and enforced coding standards which ensured the quality of solutions developed by the team.
  • Transitioned the development from a London-based team to a Warsaw-based team.
  • Created a design of the new architecture for new and existing applications.
Technologies: SQL, Entity Framework, Bitbucket, Git, Knockout (Knockout.js), jQuery, Windows Communication Framework (WCF), Web API 2, ASP.NET MVC 5, CSS, .NET, JavaScript, C#, Agile, Scrum, HTML5, ASP.NET Web API, C#.NET

.NET Web Developer

2016 - 2016
KMD Poland
  • Developed a web application that handles the complex management for utility companies in the Denmark market. Built the front end in Angular and the back end in .NET Web API 2.
  • Implemented a set of controls with a validation framework for the application, making the development process significantly quicker.
  • Ensured the high quality of the development solution by proposing and implementing code quality enhancements.
Technologies: Gulp, Git, IBM Db2, Angular, ASP.NET Web API, GitFlow, CSS, .NET, JavaScript, C#, Agile, Scrum, HTML5, C#.NET

Junior .NET Developer

2015 - 2015
AXA Direct Solutions
  • Supported a large, multi-tenanted insurance platform for AXA Group UK.
  • Worked remotely with a team mostly located in London.
  • Developed a new design for the home insurance product sales flow.
Technologies: Microsoft SQL Server, jQuery, Knockout (Knockout.js), ASP.NET MVC, CSS, .NET, JavaScript, C#, Git, HTML5, ASP.NET Web API, C#.NET


2013 - 2014
PwC (PricewaterhouseCoopers, Poland)
  • Maintained and conducted workshops for a desktop application facilitating the financial reporting process.
  • Built an entire platform, including the web app, desktop app, and web services for voting for the Polish Film Awards.
  • Developed multiple web apps used for gathering financial data from users.
  • Contributed to the statutory financial audit as an auditor, gaining knowledge about accounting processes.
Technologies: jQuery, Microsoft SQL Server, Entity Framework, ASP.NET MVC, Windows Communication Framework (WCF), Windows Presentation Foundation (WPF), CSS, .NET, JavaScript, C#, HTML5, C#.NET

App.OfferAutomation.com | Development and Technical Management

On this project, I helped deliver a web app (the front end was built in Angular 5, and the back end in ASP.NET). My primary role was to ensure the overall delivery, acting as a technical manager.

I primarily performed code reviews, ensuring the highest quality of the delivered solution. I also facilitated communication between the developers working on the project and the client, recruited new developers, proposed the high-level architecture of the solutions, and provided insight into hosting, deployment, and so on. I also created a continuous deployment pipeline using Jenkins.

TotalJobs Recruiter Platform Pricing Model Change

This large project involved 15 teams working together to change how the business worked on TotalJobs.co.uk, the largest recruitment platform in the UK.

My role as a team member was to implement the back-end logic and database layer of a new pricing model for the company. The project ended up being a big success, with the sales of the recruitment product licenses rising significantly.

Legal Platform for Contract Management

A SaaS legal product, helping companies to manage their contract/document lifecycle. I was a lead developer and helped develop several new features and integrations with platforms such as DocuSign, Zoho, or Workflow Engine, as well as an upgrade in tech to use Vue instead of .NET Web Forms.


TypeScript, CSS, HTML5, JavaScript, C#, HTML, C#.NET, SQL, SCSS


.NET, .NET Core, ASP.NET Web API, Entity, Swagger, Angular, ADO.NET, Express.js, Redux, Next.js, ASP.NET Core, Windows Communication Framework (WCF), ASP.NET MVC, ASP.NET MVC 5, Knockout (Knockout.js), Windows Presentation Foundation (WPF), ASP.NET


Vue, Vue 2, Node.js, React, jQuery, AutoMapper, Zoho API, Entity Framework, Web API 2


Git, Bitbucket, Jenkins, TeamCity, Azure DevOps Services, Jira, Visual Studio, Gulp, RabbitMQ


Agile, Scrum, REST, FluentValidation


Visual Studio Code (VS Code), Amazon Web Services (AWS), Azure, Windows, Kubernetes


MVC Frameworks, WCF Web Services, GitFlow, APIs, Front-end, Front-end Development, Episerver, Cloud, User Interface (UI), Octopus Deploy


MSSQLCE, Microsoft SQL Server, IBM Db2

2011 - 2014

Licentiate's Degree in Management

Warsaw University of Technology - Warsaw, Poland

2009 - 2014

Master of Engineering Degree in Electrical Engineering

Warsaw University of Technology - Warsaw, Poland

MARCH 2021 - MARCH 2023

Microsoft Certified: Azure Developer Associate



Microsoft Certified: Azure Fundamentals



Professional Scrum Master™ I



Microsoft Certified Solutions Developer