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Fullstack Software Engineer / Tech Lead

JavaScript + React.js, Python

About Appsilon

Appsilon is an ambitious and fast-growing software house and consultancy specializing in decision support systems and machine learning with Fortune 500 clients across the globe. We are a unique company driven by a mission to improve our society and environment. Some examples of our #AI4good work include contributing to animal preservation in Gabon Parks, building COVID-19 dashboards, and improving data science tools for Doctors Without Borders.

We are a global leader in R and Shiny, which are used by companies of all sizes to build analytical applications. When companies run into difficult problems or want to initiate large-scale enterprise projects, they come to Appsilon.

Before you apply, please read our code of conduct.

Fullstack Software Engineer / Tech Lead
JavaScript + React.js, Python

You will be responsible for:

  • Planning the architecture for software solutions
  • Designing and developing high-quality, beautiful data-centric applications
  • Writing maintainable and extendable high-quality code
  • Guiding decisions made by the team working on a project, making sure we choose good solutions, challenging unfounded assumptions and working directly with clients to discover what their true needs are
  • When necessary, lead a small (2-4 person) team of developers
  • Working with data scientists to make the models that they build usable by people, e.g. in the form of an API

What we expect:

  • Experience as a Tech Lead (you’ve made technical decisions in teams of at least 3 people)
  • Very good knowledge of JavaScript, React.js and Python is required
  • Experience in designing scalable solutions (performance testing, load balancing, microservices, deployment automation, end-to-end testing)
  • Excellent problem-solving skills
  • The ability to prototype quickly and rapidly adapt to coding challenges
  • Strong focus on business/user needs
  • Ability to learn new technologies quickly (you’ll learn R/Shiny here). If you’ve experimented with languages such as Haskell, Scala, Golang, Erlang – that’s a plus.
  • English language B2/C1 level and strong communication skills
  • Drive for high code quality, modern development practices and automated testing, and constant improvement of yourself and your team
  • Practical knowledge of CI/CD tools, Git, Gitflow, server-side cloud solutions

What we offer:

  • 17000 – 22000 PLN net/B2B
  • 26 Vacation Days
  • Approximately 11 Additional Public Holidays
  • 4 Personal Development Days to use for trainings and career development
  • Personal Development Budget: +5% on top of your gross salary that allows you to invest in your skills, mental health, or well-being
  • The latest M1 MacBook as a blazing fast machine for work
  • Employment type: we’re flexible – you can choose between umowa o prace employment (Polish residents only) or B2B. B2B contracts retain many attractive benefits such as vacation days.
  • An opportunity to work with high-profile Fortune 500 clients, including some of the world’s most important companies. Unlike other software consulting companies, who compete in the red ocean of software development, Appsilon offers scarcely available services, sought after by the largest organizations in the world.
  • Flexible working hours that let you balance a satisfying career with a robust personal life
  • A remote-first work setup that accommodates the need to complete deep work with minimal distraction
  • A smart and friendly English-speaking team with a great, non-toxic company culture. Our team members have worked for Fortune 500 companies like Google, Microsoft, and Bank of America. Many have earned PhDs and MScs from some of the best academic institutions worldwide.
  • A chance to grow your role within a young and profitable tech company driven by a positive mission. More information on our AI For Good Initiative here: https://appsilon.com/ai-for-good/
  • Semi-annual in-person company retreats when it becomes safe travel
  • Virtual assistant service via AskHenry.pl (in-person assistant service for Polish Residents)
  • Benefits for Polish residents: private health care, sport/culture card, and more
  • Continuity of projects
  • Career Guideline
  • Frequent project changes and learning about a variety of industries

What will your work look like?

  • You’ll work in a team of 2-5 people on one or two projects at a time
  • We work in an agile way (Scrum / Scrumban)
  • You’ll learn R programming language and Shiny framework
  • You will use cloud solutions, mainly AWS and Google Cloud
  • You will automate your work with Docker, Ansible, and Terraform
  • You will take care of high quality of code – an integral part of your work will be code review, unit tests, end-to-end tests and best practices that we share in our Tech Talks



Does this sound like a great opportunity for you? Write to: [email protected] or use the Apply button below!

Do you know anyone else who would be a good fit for this role? If you recommend a great candidate, you can get up to PLN 9000 from us!

Our Recruitment Process

Our recruitment process is flexible for each candidate, as we adapt it to the requirements for every open position.
Interviews with Talent Hunter and Tech Team
Recruitment Tasks and Skill Tests
Meeting with Management for a Final Decision
If you'd like to join our team, apply to one of our open positions or send an email to [email protected]

Our projects

Every few months we start completely new projects and dive into a new industry. One day we might discover the secrets of promotions in retail chains, another day we might analyze satellite images using machine learning. Our projects are not only an opportunity to test our skills in difficult statistical, algorithmic, and technological problems but also an opportunity to learn how many different industries work from the inside.

ML Building Damage Assessment

In this app, you can explore an AI model that the Appsilon AI team built for the xView2 competition. The model locates buildings and assesses damage sustained after natural disasters.


This app allows for an interactive exploration of disaster risk and development indicators in Madagascar.

Shiny Enterprise Dashboard

When we build scalable and reliable enterprise dashboards, we focus on UX and a modern aesthetic that improves our models' functionality.

see more projects

Paulina Kaczmarczyk
Paulina Kaczmarczyk
Talent Acquisition

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