Oscar Persson

Umain AB

2025 — Present

Stockholm, Sweden

Lead Front-End Engineer

Led frontend development for a large fin-tech client from inception, serving as the founding developer and establishing the project's architecture from the ground up. Drove key architectural decisions, onboarded and mentored new team members, and owned cross-functional communication between the development team and client stakeholders. Delivered a production-ready MVP within a compressed timeline, with a clean, error-free release.

• NextJS
• NestJS
• Google Cloud Platform
• Payload CMS
• Svelte
• Postman
• Selenium
• Playwright
• Storybook
• Typescript
• Claude AI
• Cursor
• Docker
• Postgres
• Github Actions
• Mailosaur API
• Sentry

Klarna

2023 — 2025

Stockholm, Sweden

Full-Stack Engineer

Accomplished back-end software engineer on Klarna's Debt Collection team, working across a Java, Spring, Kafka, and AWS stack to build efficient, scalable solutions. Contributed to the debt collection pipeline while also independently initiating and leading the development of an internal frontend service tool, owning it from concept through delivery and iterating on it based on internal and external stakeholder needs. Recognised for technical rigour, innovative problem solving, and consistently delivering high-performance systems.

• Spring
• Java
• Amazon Web Services
• Typescript
• React
• Gradle
• Docker
• Postgres
• Kafka

Spotify

2022

Stockholm, Sweden

QA Engineer

Contributed to the quality assurance process for one of the world's most widely used music streaming platforms, ensuring a seamless, production-ready user experience ahead of release. Rigorously tested critical application flows through a systematic weekly testing procedure, evaluating release stability from a user perspective and surfacing issues before they reached end users. Played a meaningful role in upholding Spotify's high bar for product quality, directly contributing to clean, error-free releases.

Skry

2022 — 2023

Stockholm, Sweden

Junior Full-stack Engineer

Worked full-stack on internal tooling, spanning a Vue/TypeScript frontend and a Ruby on Rails backend. Delivered features end-to-end based on stakeholder requirements.

• Ruby on rails
• Ruby
• Vue
• Docker
• Github
• Github Actions

Kungliga Tekniska Högskolan

2020 — 2023

Stockholm, Sweden

Lead Teaching Assistant

Led a team of teaching assistants across multiple computer science courses, including Operating Systems, Algorithms & Data Structures, Software Engineering Fundamentals, and Programming 2. Developed a structured curriculum and assistance framework to complement core course material, creating a more consistent and effective learning experience for students. Repeatedly invited back across semesters due to the consistently high quality of instruction, a direct reflection of student impact and teaching ability.

• Elixir
• Erlang
• Python
• Java

Special Elektronik

2017 — 2018

Karlstad, Sweden

Software- & Games Developer

Built VR experiences in Unity for architectural walkthroughs and customer demos. The flagship project was a 1:1 scale model of the office, fully interactive in VR. Also shipped smaller games and demo apps for both VR and desktop.

• C#
• Unity
• Blender
• Substance Painter

MSc Computer Science

(Thesis project remaining)

Kungliga Tekniska Högskolan

Relevant Courses

• Software Engineering Fundamentals
• Advanced Algorithms
• Dynamic Programming & Interactive Web Design
• Large-Scale Software Development
• Automated Software Testing and DevOps
• Software Reliability

BSc Information & Communication Technology

Kungliga Tekniska Högskolan

Relevant Courses

• Data Storage Paradigms
• Modern Software Development
• Algorithms, Datastructures & Complexity
• Logic for Computer Scientists