Daniel Karlsson, Developer in Stockholm, Sweden
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Daniel Karlsson

Verified Expert  in Engineering

Software Developer

Stockholm, Sweden
Toptal Member Since
July 2, 2018

Daniel is a full-stack developer and co-founder of a startup called Fliffr. Over the past three years, he designed, architected, implemented, and maintained both back-end and front-end software. As a founder, he's driven and a self-starter, and as an employer of freelancers, he knows what goes into good communication at both ends of a remote working relationship. He prides himself on being able to independently solve problems.


TypeScript, JavaScript, PHP, Vue, Vuetify, Docker, Docker Compose, Terraform...
Ionic 4, Angular, Laravel, Spring
Cordova, Android, iOS, Django, Ionic, Angular, Go




Preferred Environment

Visual Studio Code (VS Code), Unix, Git

The most amazing...

...thing I've done was found a startup as a technical co-founder. I got to experience the whole product lifecycle.

Work Experience

Lead Front-end Developer

2020 - PRESENT
  • Implemented a DevOps approach and moved the team from monthly deploys to daily deploys with a change fail rate below 0.05%.
  • Rewrote a large legacy application from jQuery to Vue.
  • Introduced automatic quality controls like linters, type checking, unit, and E2E tests allowing the team to increase velocity while minimizing defects.
Technologies: TypeScript, JavaScript, PHP, Vue, Vuetify, Docker, Docker Compose, Terraform, Amazon Web Services (AWS), Apache Kafka, KSQL, Cypress, Jest

Full-stack Developer

2019 - 2020
  • Architected the back-end and front-end applications.
  • Worked closely and iteratively with clients to deliver products.
  • Improved TDD and CI/CD practices to deliver more stable software.
Technologies: Ionic 4, Angular, Laravel, Spring

Founder/Full-stack Developer

2015 - 2018
  • Developed back-end and front-end from scratch.
  • Managed product and released the application for Android and iOS.
  • Led business development from a technical standpoint.
  • Worked with B2B partners to build customized white label solutions of the Fliffr tech.
  • Led testing work including setting up workflow and CI.
Technologies: Cordova, Android, iOS, Django, Ionic, Angular, Go

Support Technician

2011 - 2012
Stockholm County Council, IT Support in Healthcare
  • Learned how to turn any situation, (almost) no matter how bad, into something positive for the customer.
  • Developed scripts to automate helpdesk work such as troubleshooting and applying simple fixes.
Technologies: Windows, Azure Active Directory


Fliffr is an application for on-demand help via live video.

I did front-end and back-end work including integrating WebRTC and Stripe payments and releasing apps for iOS and Android.


A pivot of Fliffr where we used the same underlying technology to create a new offering for a new segment. This project reinforced my Angular 2 skills as well as quickly delivering a completely new front-end application.
2012 - 2015

Coursework Toward a Bachelor's Degree in Computer Engineering

KTH Royal Institute of Technology - Stockholm, Sweden


Vue, WebRTC, Stripe API


Git, Docker Compose, Terraform


Angular, Vuetify, Ionic 2, AngularJS, Django, Cypress, Spring, Laravel, Ionic 4, Ionic, Jest


Amazon Web Services (AWS), Android, Linux, Amazon EC2, Unix, Visual Studio Code (VS Code), iOS, Windows, Docker, Apache Kafka


Java, Python, TypeScript, Go, TypeScript 2, CSS3, HTML5, SQL, JavaScript, PHP


Amazon S3 (AWS S3), Azure Active Directory, PostgreSQL


Functional Programming, Continuous Integration (CI)


Cordova, AWS DevOps, KSQL

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