Justin Sijbolts
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about me

Justin Sijbolts

justin sijbolts 江哲

Hi! I'm Justin Sijbolts - online nickname Boltfish, a 21-year old software engineering student born in the Netherlands. Currently, I live in Chengdu, China . It's currently 1:42 AM where I am, with loading... at around loading....

Global Game Jam Groningen Best Interaction Award GGJ Groningen 2024
汉 HSK2 100% chinese proficiency
7.5 IELTS 7.5 english proficiency

projects

BoltConnect
BoltConnect 2026

A student information system featuring homework submission and tracking, attendance tracking, graduation project professor-student matching, and scheduling.

SQL PHP JS CSS HTML
Chengdo
Chengdo 2026

A management dashboard for university Overseas Offices and students, accessible via a WeChat Mini Program and website, enabling students to view the bureaucratic steps they need to complete while allowing Overseas Office staff to add and manage them. Making a process that was previously overwhelming and unclear a bit easier.

SQL PHP JS CSS HTML
Smash'k
Smash'k 2026

A local multiplayer co-op adventure for 2–4 players, made during the Global Game Jam 2026 (Groningen) under the theme "Mask." Designed core gameplay mechanics including mask-based world-shifting abilities, character transformations, and physics-driven combat.

C# Unity
PartydoosMedia
PartydoosMedia Web v4 2025

Website developed in preparation of PartydoosMedia its acquisition, featuring high level editability and customisation by using Advanced Custom Fields. Utilises WordPress as the CMS, with a custom highly adaptable theme, later sold to startups too, built from scratch.

WordPress PHP JS SQL ACF WHMCS Stripe TranslatePress
Flytrack
Flytrack 2025

Flytrack is a PWA mobile app that allows users to track, log, and view everything about their flights. From diversions and delays to viewing interesting statistics like average delay times, favourite airlines, and most frequently flown routes.

PHP SQL JS APIs PWA CSS HTML
Double Bubble Trouble
Double Bubble Trouble 2024

A chaotic co-op game in which two players, shrunk and trapped inside a giant bubble, bounce their way through a twisting sewer system back to the surface. Designed collaborative gameplay mechanics centered around teamwork, obstacle dodging, and physics-based bouncing.

C# Unity
Evapay
Evapay 2024

A complete web-based payment platform that grew from a personal project into a full-featured solution.

Built a customisable payment page for organizations and a flexible invoice generator compliant with all Dutch government requirements, along with personalized payment links via Stripe and Mollie supporting custom logos, colors, and branding.

Implemented multi-account support with role-based access control for team members, from administrators to accountants, and ensured a fully responsive design that works smoothly across all devices and screen sizes.

PHP SQL Stripe Mollie JS APIs PWA CSS HTML
Evapay Invoicing
Evapay Invoicing 2024

Evapay Invoicing is as an integrated feature of the Evapay platform, enabling users to link invoices directly to transactions for improved organization. Built a system compliant with all Dutch invoicing regulations, offering customisable document options from fonts to specific details, with PDF export for each invoice.

Integrated advanced AI technology that automatically verifies invoice data including IBAN numbers and company information to ensure accuracy and prevent errors.

PHP SQL JS APIs CSS HTML
Liava: Crazy Wipeout
Liava: Crazy Wipeout 2024

A splitscreen co-op racing game inspired by Wipeout, made in 48 hours for the Global Game Jam 2024 (Groningen) under the theme "Make Me Laugh." Designed competitive gameplay featuring checkpoint-based scoring, power-ups, and sabotage mechanics, earning the "Great Interaction" Award.

Built splitscreen multiplayer supporting Xbox controller and keyboard-and-mouse input, with compatibility for Steam Remote Play Together.

C# Unity
Quci
Quci 2023

Challenged myself to develop a Twitter clone in 48 hours, including profile customisation, personalised feeds, user interaction, settings, and full post functionality.

PHP SQL JS CSS HTML
Sands of Fate I
Sands of Fate I 2023

Worked on advanced water simulation and developed an advanced multi caption rendering system in Unity, allowing for dynamic and interactive gameplay.

C# HLSL Unity
Krakout 2: Professional Lite
Krakout 2: Professional Lite 2023

Recreated Krakout 2: Professional, a Commodore 64 original using RT2D, a 2D OpenGL game framework.

C++ OpenGL
Shooting Game
Shooting Game 2022

Worked on a first-person shooter, where players connect through custom Steam multiplayer networking and connect to a server to verify details such as connection status, update status and game status. Syncing bullets, players, game status, UI and advanced physics.

SQL APIs C# Unity Steam
Streamotion
Streamotion Iris Editor 2022

Worked on a platform allowing for vector photo editing through a custom tool called Iris Editor, allowing clients to customise their purchased vector product to their liking. Also implemented an automatic tool to import products into their existing software.

PHP SQL JS APIs C#
Magic Golf
Magic Golf 2022

Magic Golf was made during my Software Development studies at Alfa-college (originally Game Development), it's a multiplayer golf game that evolved from a simple concept into a creative and unique experience. Designed a "modifier card" system in which players select special cards at the start of each round to transform their opponent's golf ball into elements such as ice, fire, magnet, or rock, each affecting ball movement and bounce to create one-round challenges and strategic advantages.

Implemented multiple control schemes including keyboard, standard gaming controllers, and a custom-built physical controller ("Golfmote") designed specifically for the game to enhance the playing experience.

C# Unity

work experience

PartydoosMedia Operations Manager Remote Jul '25 – Present Founder, CEO the Netherlands Aug '14 – Jul '25
Aug '14 – Present
Convident Frontend Developer Groningen, the Netherlands Sep '24 – Feb '25
MNTN digital Full-stack Developer Groningen, the Netherlands Sep '23 – Feb '24
Uitgeverij Instruct Various Support Developer Remote Apr '23 – Mar '24

education

四川大学 Sichuan University Software Engineering (Bachelor) Chengdu, China 2025 – 2029
Alfa-college Software Development Groningen, the Netherlands 2021 – 2025
Dollard College MAVO, Economic Specialisation Bellingwolde, the Netherlands 2017 – 2021

companies i've worked with

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