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stefan matić

Work

Systems I've built, and what they changed

6 in-depth case studies, plus 15 more projects across travel, education, sports, healthcare, legal, HR and government.

Showing 6 case studies

Hostelworld: system diagramA booking platform used around the world was running on ageing code. I helped move it onto six modern codebases while guests kept booking, then built what came next: sign-in at the gateway, AI features and a paid subscription.LEGACYExpress · MariaDB6+ NX MONOREPOSNestJSGATEWAYApigee · authLINKUPS APPVue · PlaywrightDATAMongo · Firestore · RedisSOCIAL PASSGoogle Play
Plate 01Travel

Hostelworld

0 regressions on live traffic

NestJSNxTypeScript
edio: system diagramA US online school with 20,000+ students is rebuilding its platform. I help ship version 3, rewriting old features and building new ones side by side, while the current version keeps working for students, teachers and parents.SHARED LIBRARIESReact · Git submodulesEXAMScreate · takeGRADINGgrades · reviewSTUDENTSmanagementPROGRESStracking · feedback
Plate 02Education (US K–12)

edio

One library behind 20,000+ learners

ReactTypeScriptTanStack Query
Atlas Sports Analytics: system diagramLive sports data arrives messy and fast. I've worked across the whole pipeline, from the service that collects raw StatsPerform data to the app fans use, so live scores and stats reach the screen accurately.STATSPERFORMraw dataPROVIDERNestJS · CQRSCONSUMERgRPC · NestJSDATAMongoDBBFFNestJS · CQRSFRONTENDAngular · RxJS
Plate 03Sports analytics

Atlas Sports Analytics

Predictable latency under sustained load

NestJSCQRSTypeScript
LogiTrack: system diagramA trucking company needed one place to run its whole operation: vehicles, fuel, drivers, partners, invoices and documents. I designed and built the entire frontend from an empty repository.COMPONENT SYSTEMRadix · shadcn · TailwindDATA LAYERTanStack QueryTABLESTanStack TableFORMSReact Hook Form · ZodMODULES
Plate 04Logistics

LogiTrack

Entire frontend architected from zero

ReactTypeScriptTanStack Query
Data Context Hub: system diagramSome problems only make sense when you can see them. I built an interactive canvas where people explore graphs, algorithms and big datasets, and it stays smooth as the data grows.CANVASReact FlowCANVAS STATEZustandDATATanStack QueryTABLE VIEWTanStack Table
Plate 05Data visualisation

Data Context Hub

Real-time interaction on large datasets

Next.jsReact 19TypeScript
Attorneys: system diagramA law practice needed software to manage debt cases from first contact to final payment. I led the project from the first conversation to production and owned every layer.INTERFACEReactAPIExpress · TypeScriptDATAPostgreSQL · Knex
Plate 06Legal / finance

Attorneys

Led from concept to deployment

PostgreSQLKnexNode.js
Index

More projects

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07StatsPerformReal-time sports statisticsKey frontend role; live updates over WebSocketsAtes Soft

Played a key role in a live sports analytics product. Implemented real-time updates over WebSocket connections and built features for live stats, scores and play-by-play. React, TypeScript, Redux-Saga.

ReactTypeScriptRedux-Saga
08TelemedicinaOnline healthcare appointments: video, chat, phoneSole frontend developer; UI design and SEOAtes Soft

Built the whole frontend for video, chat, phone and email consultations, designed the interfaces and handled SEO. React, SockJS, Daily API, JWT, Figma.

ReactTypeScriptSockJSDaily APIJWTFigma
09HR ConnectRecruiting, payroll and engagementKey contributor across the stackAtes Soft

Social features, leave requests and performance reviews. PostgreSQL, Express, React, Redux Toolkit, Chakra UI, i18next.

PostgreSQLExpressReactRedux ToolkitChakra UIi18next
10Simwave AcademyMaritime training and assessment platformFull stackAtes Soft

Training, assessments and online courses for the cruise industry. Next.js, Express, GraphQL, Prisma, Strapi, Docker.

Next.jsExpressGraphQLPrismaStrapiDocker
11FABMedical guidelines managementLed the PoC: estimation, proposal, stack selection, PR reviewAtes Soft

Estimation, proposal, stack selection, project board and PR review for the delivery team.

12NanoInternal social platformVideo features: autoplay, progress, likes, commentsDEVLEGION

Internal social platform. Built video features: autoplay, progress tracking, likes and comments. React, Redux.

ReactRedux
13LexaLegal case and hearing managementFeatures and fixes in an existing codebaseDEVLEGION

Legal case and hearing management platform. Shipped features and fixes in an existing codebase. React, Zustand, TanStack Query, shadcn/ui.

ReactZustandTanStack Queryshadcn/ui
14DEVLEGION websiteCompany marketing siteCo-designed and built; SEO and analyticsDEVLEGION

DEVLEGION's company marketing site. Co-designed and built it, including SEO and analytics. Next.js, Next UI, Microsoft Clarity.

Next.jsNext UIMicrosoft Clarity
15AmbitiewebSustainability tracking and chartsFrontend lead, plus backendAtes Soft

Sustainability tracking and charts platform. Frontend lead, plus backend work. Angular, Chart.js, PHP, Zend.

AngularChart.jsPHPZend
16Luminaire BrokerLighting specifier and supplier platformSEO, features, major refactoringAtes Soft

Lighting specifier and supplier platform. Worked on SEO, new features and a major refactoring. React, Redux, Material UI.

ReactReduxMaterial UI
17StetoskopClinic appointment bookingLed the frontend designAtes Soft

Clinic appointment booking platform. Led the frontend design. React, Tailwind, Ant Design.

ReactTailwindAnt Design
18Site ViewConstruction management MVPFrontend under tight deadlinesAtes Soft

Construction management MVP. Built the frontend under tight deadlines. React, Angular, Redux, Figma.

ReactAngularReduxFigma
19ScramblingTV program schedulingFixed critical issues on a live platformAtes Soft

TV program scheduling platform. Fixed critical issues on a live platform. React, Sass, Ant Design.

ReactSassAnt Design
20KLERPGovernment economic development portalNew pages, complex business logicAtes Soft

Government economic development portal. Built new pages with complex business logic. React, Sass, JWT.

ReactSassJWT
21HR Management AppInternal HR system (first project)Refactored ASP.NET MVC to a server component; UI redesignAtes Soft

Stefan's first project: an internal HR system. Refactored it from ASP.NET MVC to a server component and redesigned the UI. ASP.NET MVC, .NET.

ASP.NET MVC.NET
Have a project?

Let's build the whole thing properly.

An MVP, a rebuild, or a system that has to survive launch day. Tell me what you're building in a 30-minute call.

Book a 30-min callmaticstefan1996@gmail.com
Need an engineer on your team?

Senior full-stack, remote, CET.

Available as a long-term contractor on a monthly rate, embedded in your team, or full-time. Seven years across React, Node and the cloud, plus CTO experience.

Discuss a contractDownload CVLinkedIn →