Top 15 Kotlin Development Firms in Serbia

Finding a reliable Kotlin development partner in Serbia is challenging when buyers must assess technical competence, Kotlin-specific experience, and the ability to deliver stable, maintainable code on schedule. Buyers should compare team size and seniority, Android versus backend Kotlin expertise, CI/CD and testing practices, security and IP terms, communication and English proficiency, and cost and contract flexibility.

SoftPro is the featured international partner leading this list and serves buyers across the region. Assess SoftPro and other firms by reviewing relevant portfolios, client references, development workflows, scalability for future phases, and support and maintenance arrangements.

1. SoftPro

SoftPro is the featured international partner on this Top 15 Kotlin Development Firms in Serbia list, chosen for readers seeking reliable external engineering teams that can deliver backend, web and cloud projects into the Serbian delivery market. This placement highlights SoftPro as a cross-border development partner suited for enterprise portals, SaaS platforms and complex web applications where remote delivery and integration with regional teams are required.

Their engineering team works with Azure, ASP.NET and .NET Core within the Microsoft stack to deliver enterprise CMS implementations and carry out complex cloud migration projects. The company combines frontend, backend and platform CMS experience to support modernization, ongoing maintenance and platform migrations for business-critical systems.

Key Highlights

• Active cloud practice delivering on both Microsoft Azure and AWS.
• Frontend and API stacks include React and for modern web applications.
• Public case studies show work on Umbraco websites, CRM/HRM systems, SaaS ETL platforms and business portals.
• Over 20 years of combined team experience with continuous support and maintenance for delivered systems.

Services

• Software development
• Web application development
• Cloud-native development
• Artificial intelligence

Contact Information

Website: soft-pro.pl

Phone: +48 571 282 759

Address: Poland, Warsaw, Mazowieckie Voivodeship, 13 Erasmus Ciołka St. 401

LinkedIn: www.linkedin.com/in/kyrylo-o

2. Aetherius Solutions d.o.o.

Aetherius Solutions d.o.o. is a Niš-based mobile development firm that builds native iOS and Android apps and cross-platform applications using Kotlin Multiplatform and Compose Multiplatform. The company’s senior, mobile-only team emphasizes production-ready KMP expertise and supports both new Kotlin Multiplatform projects and migrations of existing apps, which aligns with Kotlin-focused development needs in Serbia.

Aetherius operates with a Europe-aligned delivery model and positions itself to integrate with client teams for long-term mobile product work. Their focus on Kotlin Multiplatform and Compose Multiplatform gives clients a clear Kotlin-centric engineering path for cross-platform mobile projects.

Key Highlights

• 10+ years of experience in mobile development.
• 75+ projects delivered across mobile platforms.
• Engagement models include Team Augmentation, Outsourced Team, Part-Time Dedicated Developers, and Sprint-Based Team.
• 98% client satisfaction score shown on the company site.

Services

• Team Augmentation
• AI App Development Services
• UI/UX Design Services
• Maintenance and Support Services

Contact Information

Website: www.aetherius-solutions.com

Phone: +381 69 520 2997

Email: contact@aetherius-solutions.com

Address: Dimitrija Leka 64, Niš

Address: 32 N Gould St, Sheridan WY 82801, Wyoming

LinkedIn: linkedin.com/company/aetherius-mobile-app-development-company

3. Heco Tech d.o.o.

Heco Tech d.o.o. is a Niš-based engineering studio that builds mobile-first native iOS and Android applications and AI-driven architectures. The studio focuses on fast, production-ready delivery and ownership of the product lifecycle from concept through App Store release.

The team applies Kotlin and native platform toolkits to share logic where it accelerates delivery and to integrate on-device and cloud AI into mobile products. Their approach pairs native performance with pragmatic cross-platform sharing to fit Kotlin-focused development needs in Serbia.

Key Highlights

• Operating since 2022.
• Led a Kotlin Multiplatform implementation for Manigo fintech with 85% shared code, 40% development time saved, 12+ brands launched and 99.99% uptime.
• Offers a two-week discovery phase with fixed scope and fixed-price engagement before development starts.
• Toolbelt lists Edge LLMs, CoreML, PyTorch, and TensorFlow Lite for on-device or cloud AI deployments.

Services

• AI Integration
• Design Systems
• Web Development

Contact Information

Website: www.hecotech.dev

Email: office@hecotech.dev

Address: Office 18000 Niš, Serbia

LinkedIn: linkedin.com/company/heco-tech

4. TMS Outsource

TMS Outsource is a custom web and mobile application development agency with engineering teams based in Belgrade, Serbia and Bucharest, Romania. They work with startups and scale‑ups across Europe and North America to plan, build, support, and enhance production software for web and mobile platforms.

The company explicitly lists Android (Kotlin) in its mobile technology stack and runs end‑to‑end engagements that start with scoping and technical workshops and continue through development, QA, and post‑launch support. This delivery model and stated Kotlin capability make TMS Outsource a practical option for teams looking to hire Kotlin developers in Serbia.

Key Highlights

• 40+ engineers across Belgrade and Bucharest.
• Founded in 2014.
• Recognized by Deloitte Fast 50 and rated 5.0 on Clutch.
• 4.2M+ active installs across TMS-built WordPress products such as Amelia and wpDataTables.

Services

• Mobile app development
• Web application development
• Product engineering
• DevOps & cloud

Contact Information

Website: tms-outsource.com

Phone: +40 771 013 429

Email: hello@tms-outsource.com

Address: Velisava Vulovica 18, 11000 Belgrade, Serbia

Address: Ion Mihalache 106, Bucharest, Romania

5. Qwertify

Qwertify is a full-cycle software development company based in Belgrade that designs and builds user-centered mobile and web products. The team emphasizes UX-led product strategy and engineering to create native Android applications implemented with Kotlin.

Qwertify supports work from MVPs through scaling and refactoring by embedding cross-functional teams into client workflows and delivering agile product releases. This combination of Kotlin expertise, product discovery, and design-led delivery positions the company as a practical choice for Kotlin development projects in Serbia.

Key Highlights

• Portfolio highlights include mobile apps such as Linguado and My Patrol.
• The published technology list includes hybrid mobile frameworks React Native and Flutter for cross-platform projects.
• Backend and server-side technologies explicitly listed are PHP (Laravel), Node.js, Java (Spring Boot), and databases MySQL, SQL Server, and MongoDB.
• The careers page shows active hiring with open roles like Medior Android Developer and Senior React Native Developer in Belgrade.

Services

• Outstaffing solution
• Project-based solution
• UX/UI Design

Contact Information

Website: qwertify.io

Email: info@qwertify.io

Address: Kondina 13, Belgrade, Serbia

6. Gecko Solutions d.o.o.

Gecko Solutions d.o.o. is a Belgrade-based software engineering company that delivers end-to-end product development from concept to production while applying iterative delivery and formal project tracking. The firm emphasizes secure, production-ready delivery with a process that combines Agile, Lean, and Unified Process elements.

The company has experience building native Android and iOS applications and full web platforms, which demonstrates capacity for Android-focused projects and makes them relevant for Kotlin development listings. Their delivery approach targets early usable releases and continued support for mobile-first products.

Key Highlights

• ISO/IEC 27001:2022 certified for Software Development Services and Software Product Development.
• Holds a Platinum Creditworthiness Certificate based on financial statements for the last three fiscal years.
• Established on 27 July 2010 and headquartered in Belgrade.
• Has invested in two product companies, Stynt and Beam; Stynt’s web and native Android and iOS apps were developed by Gecko Solutions.

Services

• UI/UX Design
• Infrastructure & DevOps
• TAAS
• Digital Banking

Contact Information

Website: www.gecko.rs

Phone: +381 11 21 29 724

Email: office@gecko.rs

Address: Užička 10, 11040 Belgrade, Serbia

7. IT Engine d.o.o.

IT Engine d.o.o. is a Novi Sad–based software engineering company that builds custom web and mobile systems from concept through production and maintenance. Their project portfolio includes native Android work, and the site lists Kotlin in its partner network and shows Android apps like Track4Outdoors in the projects section.

The company coordinates partner collaborations to bring additional Kotlin Android expertise into project teams while handling requirements analysis, testing, deployment, and ongoing maintenance.

Key Highlights

• The company reports 12 years in the industry on its official site.
• The site lists a headcount of about 50 employees.
• IT Engine states it has completed over 100 successful projects.
• The firm maintains offices in Novi Sad, Serbia and Stockholm, Sweden and notes work across six continents.

Services

• Software Development
• Mobile Development
• Quality Assurance
• UX/UI Design

Contact Information

Website: itengine.rs

Email: office@itengine.rs

Phone: +38121533400

Address: Marka Miljanova 3, 21000 Novi Sad, Vojvodina, Serbia

Email (Stockholm): sandra.ekstrom@itengine.se

Phone (Stockholm): +46735932404

Address (Stockholm): Bersågränd 62, 12131 Enskededalen, Stockholm, Sweden

LinkedIn: linkedin.com/company/itengineserbia

8. Urban Signal

Urban Signal is an independent software consultancy led by Djordje Rakonjac and based in Belgrade, Serbia. The practice engineers production-grade systems across backend, frontend, and mobile with end-to-end technical ownership from concept to deployment.

The studio is a fit for a Kotlin development list because it delivers production-ready mobile applications alongside full product engineering and cloud integration, enabling native app delivery within disciplined CI/CD and operational processes.

Key Highlights

• Mobile development explicitly lists Android (Kotlin) as a supported native platform.
• Engagement models include dedicated teams, embedded engineers or tech leads, project-based delivery, and advisory consulting.
• Cloud and DevOps capabilities cover CI/CD automation and multi-cloud infrastructure across AWS, GCP, and Azure.
• AI offerings include LLM and RAG systems plus MCP-based AI agents with cost, observability, and reliability controls.

Services

• End-to-End Product Engineering
• Mobile Application Development
• AI & LLM Solutions
• DevOps & Cloud Infrastructure

Contact Information

Website: urbansignal.io

Address: Belgrade, Serbia

9. Neopix (weareneopix)

Neopix is a UX- and data-driven digital product studio that combines product design, engineering, and analytics to build end-to-end web and mobile products. Their engineering section explicitly lists mobile app development and Android engineers, which makes them a relevant Serbian partner for Android projects that are commonly implemented with Kotlin.

They run greenfield 0–1 product development with full-stack teams to move ideas to working products. Their Product Team Augmentation model lets clients scale feature teams up and down for delivery and hands-on collaboration.

Key Highlights

• 10+ years of experience delivering work for non-profits, funded startups, government institutions, and global enterprises.
• Maintains offices in Niš, Serbia; Delaware, USA; Sydney, Australia; and Dubai, UAE.
• Design capabilities explicitly list Design Systems & Style Guides, Product Prototyping & Optimization, and Motion Design.
• Engineering capabilities include Application Monitoring, Performance Optimization, and Quality Assurance for production systems.

Services

• UX/UI Design
• Design Systems & Style Guides
• Product Analytics
• Quality Assurance

Contact Information

Website: www.weareneopix.com

Phone: +381 60 6362 300

Email: hello@weareneopix.com

Address: Europe: Kraljevića Marka 23, 18000 Niš, Serbia; USA: 2140 S Dupont Highway, 19934 Delaware; Australia: Suite 2003, Level 20, 109 Pitt Street, Sydney NSW 2000; UAE: Level 3, Boulevard Plaza Tower 1, Downtown, Dubai

10. COING (Clockify team)

COING is a Novi Sad, Serbia–based product team whose homepage opens with the tagline "We build great ideas" and an invitation to collaborate. The site frames the company around product work and points visitors to a contact page and open positions for engagement.

The homepage highlights COING's involvement with established app products, which positions the firm as a relevant Serbian candidate for teams researching Kotlin development vendors in the region.

Key Highlights

• Headquartered at Bulevar Oslobođenja 127, Novi Sad, Serbia.
• Phone listed as +381 (21) 300-13-50 on the contact page.
• Names Clockify, Pumble, and Plaky among its biggest clients.
• Careers link routes to for open positions.

Services

• Time tracking app
• Business communication app
• Task management app

Contact Information

Website: coi.ng

Phone: +381 (21) 300-13-50

Address: Bulevar Oslobođenja 127, Novi Sad, Serbia

11. Nistruct d.o.o.

Nistruct is a Serbian software development company that builds scalable, secure applications across web, backend, and data domains to support business workflows. The firm positions itself to deliver end-to-end projects with attention to data security and long-term client engagement.

The company’s public team listing shows a lead mobile developer and several Android engineers, which suggests they can staff Kotlin-based Android projects when clients require that stack. This inference is based on the team roster published on the company site.

Key Highlights

• Partners and clients listed on the site include Hostelworld, Leanpay, 3DH Labs, and Planeta Sport.
• A client testimonial notes Nistruct supplied two experienced developers and an experienced project manager for a Java project.
• Client feedback highlights embedded, long-term team delivery where Nistruct engineers integrate closely with client engineering teams.
• The company lists its office location as Niš, Serbia and shows business hours of 9h-17h UTC+1 on the site.

Services

• Mobile Development
• Backend Development
• Testing & QA
• Data Analysis & AI

Contact Information

Website: nistruct.com

Phone: (381) 69 1046701

Email: info@nistruct.com

Address: Niš, Serbia (nistruct.com)

12. Falcon-Tech d.o.o.

Falcon-Tech d.o.o. is a Novi Sad software company that develops custom web, desktop, and mobile applications for Serbian enterprises and public institutions. The team implements Android applications using Kotlin and Java and integrates those apps with backend systems and databases.

Their delivery model pairs native Android builds with responsive backends and Linux-based deployments to provide end-to-end solutions that require Kotlin expertise and cross-platform integration.

Key Highlights

• Founded in 2009 and headquartered in Novi Sad.
• ISO 27001 certified for information security management.
• Notable clients include RATEL, the University of Novi Sad, and the Provincial Government of Vojvodina.
• Registered VAT number 106047273 and company ID 61761268 in the Serbian business register.

Services

• AI & machine learning solutions
• E-commerce development
• Web and graphic design
• IT training and consulting

Contact Information

Website: falcon-tech.rs

Phone: +381 62 8311 667

Address: Braće Ribnikar 50, 21000 Novi Sad, Serbia

13. Appomart

Appomart builds full-cycle mobile applications and web services, delivering design, backend APIs, testing, and production launches for client and enterprise projects. The team emphasizes parallel development of server, web, and mobile components to shorten delivery timelines and provide ongoing technical support.

Appomart operates a platform-driven workflow that coordinates documentation and simultaneous server, web, and mobile engineering. That delivery model and their Android-focused product experience make Appomart a practical candidate when evaluating Kotlin-capable Android development partners in Serbia.

Key Highlights

• Earned TechBehemoths top rankings in Serbia for Web Development, Mobile App Development, and ReactJS in 2025.
• Named among 2025’s leading cloud consulting companies by.
• Lists Google Cloud, DigitalOcean, and Stripe among its publicly shown technology partners.
• Founder Vladimir Chernyi was awarded IEEE Senior Member status in December 2024.

Services

• Research & Marketing
• UX/UI Design
• Gamedev on Unity3D
• Professional legal support in IT

Contact Information

Website: appomart.com

Phone: +381 (69) 222-23-28

Phone: +972 (55) 295-08-54

14. Marble IT

Marble IT is a Novi Sad software studio that builds custom web, mobile, and game projects, delivering everything from web APIs to interactive experiences.

Its product-minded engineering and cross-platform mobile experience, paired with a consulting-first approach, make Marble IT a logical partner for Android engagements in Serbia that commonly rely on Kotlin-based development.

Key Highlights

• Tech stack lists cross-platform mobile frameworks including React Native and Flutter alongside Unity and C#.
• Game development services explicitly include game programming in Unity and Unreal plus 2D/3D art and animation.
• The studio lists AR/VR and real-time 3D capabilities, including Unity AR Core and Unity AR Kit.
• Marble IT advertises a free introductory consultation call to help scope projects and shape mobile roadmaps.

Services

• Team augmentation
• Fixed-scope product development
• Game co-development

Contact Information

Website: marbleitsoftware.com

Email: office@marbleit.rs

Address: Bulevar Evrope 23, Novi Sad, 21000 Serbia

15. SpiceFactory

SpiceFactory is an AI deployment studio that builds production AI systems for regulated industries. The firm combines precision engineering and clean architecture to move projects from prototype to production in complex technical and compliance environments.

The company maintains a Belgrade office and focuses on mobile, embedded, and IoT engineering, positioning it as a Serbia-based partner for teams building production mobile and embedded applications. Its delivery model emphasizes measurable outcomes and handoff of capability to client teams.

Key Highlights

• The site documents a three-SKU Studio Model that packages delivery into distinct engagement types.
• A 5-day Deployment Bootcamp is offered to ship a working agent on a client’s real data.
• Deployment Pods are scoped to ship one regulated-AI milestone every six weeks.
• Outcome Contracts name a binary state-change and gate final payment on achieving that outcome.

Services

• Applied AI
• Embedded Systems
• Infotainment & Connected Car
• Regulatory compliance engineering

Contact Information

Website: spicefactory.co

Address: 100 Cambridge Street 14th Floor, Boston MA 02114 / United States

Address: Trg Nikole Pasica 5, Belgrade 11000 / Serbia

Conclusion

SoftPro is the featured international partner on this Top 15 Kotlin Development Firms in Serbia list and is highlighted for readers seeking reliable external engineering teams. Use this curated list to narrow options rather than assuming a single optimal provider.
When choosing, prioritize fit to your project: match the engagement model to your needs, verify Kotlin expertise including Kotlin Multiplatform if you require shared code, confirm production and maintenance capabilities, and weigh domain experience for regulated or enterprise work. Also consider UX and data strengths for product-driven projects, practical factors like team seniority, time zone and language alignment, and validate the team with references or a short pilot before committing.