Search for a Backend Developer (Kotlin + Spring Boot) for a large-scale mobile service Smart Mobility
300 USD We are looking for an experienced Backend Developer for long-term work on a large commercial project Smart Mobility — a full-fledged real-time ride-hailing service (like Uber/Bolt/BlaBlaCar), but with enhanced social interaction and unique POOL trip algorithms.
❗ IMPORTANT
The current project is not suitable for PHP. We need a specialist who:
is proficient in Kotlin + Spring Boot 3,
understands multithreading, low-latency, WebSockets, real-time logic,
has experience building high-load APIs,
works with geolocation, event queues, Redis/Kafka,
can design scalable architecture.
📌 Stack (mandatory)
Kotlin
Spring Boot 3
WebFlux (reactive stack)
PostgreSQL
Redis
WebSocket
Docker
Advantage: Kafka, Firebase, Mapbox/OSRM routing API
📌 Brief about the project
Smart Mobility is a service that includes:
individual and shared POOL trips;
POOL algorithm
real-time passenger matching;
group rooms (Rooms) with chat;
private chat “Nearby” between passengers;
Secure Ride (live tracking for trusted persons);
No-Show logic, referral scenarios, social statuses, ratings;
separate functionality for drivers (cooperative).
There is a lot of work to do. This is not a “simple taxi”.
We need a specialist who understands complex systems and is ready to participate in the development of the complete backend core.
📌 Requirements
3+ years of commercial development on JVM (Kotlin or Java).
Experience with microservices, real high-load APIs.
Understanding of concurrency, race conditions, fault tolerance.
Ability to design data models and complex business logic.
📌 Tasks for the near future (MVP Backend)
Authorization/roles (passenger/driver)
Trips & POOL Engine (Base, Extra, Required Payout)
Matching
FSM states of the trip
Rooms + WebSocket Chat
Secure Ride (live tracking)
Implementation of tariffs (SOLO/POOL)
Logging of critical events
📌 What we offer
complete technical specifications, including formulas, logic, scenarios;
access to all UI mockups and requirements;
technical support and product maintenance;
adequate budget if the level matches.
If you are a specialist in Kotlin/Spring Boot and love complex tasks — we look forward to your response.
Further – payment step by step, for each module separately.
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7 days300 USD
7 days300 USDI am looking for a long-term project with 20 years of experience. Spring Boot 3, Redis/Kafka, Postgres, etc. The rate is formal, I am ready to discuss the details.
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5 days300 USD
164 5 days300 USDHello! 👋 You are greeted by Anastasia, the 256Devs team. We provide services of qualified Backend developers who specialize in Kotlin and Spring Boot for creating high-performance and reliable enterprise solutions. We guarantee clean architecture, adherence to deadlines, and effective integration into your current or new project. Please send a description of the tasks or project for scope assessment.
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5 days300 USD
475 5 days300 USDЗдравствуйте!
Меня зовут Алексей, я представляю группу разработчиков – NC-1.
В нашей команде есть специалист (mobile-developer, senior) с необходимыми для Вас опытом и знаниями. Ставка в час - 26 usd.
Стек: Java, Kotlin and Dart.Git, GitFlow, Github and Bitbucket. Room, Active Android,GreenDao. Kotlin Coroutines and RxJava2. XML and JSON.Postman, SoapUI & Figma. Simple XML Parser, GSON, Moshi and Retrofit 2. HTTP Url Connection, Asynchronous HTTP Client, OkHttp2.CHUCK.Lint, KtLint. MVP, MVVM and MVVM + clean architecture. Dagger Hilt, Dagger2 and Koin. Jira, Trello. SOLID, Dry. XML & Jetpack Compose.CameraX (ImageCapture and VideoCapture). Espresso, UI Automator. JUnit 4, Truth, Mockito and Mokk. Google play console, Firebase app distribution and Fastlane.SwiftUI, SwiftData, R.Swift. AppWrite
Кейсы: https://1drv.ms/b/c/b7a0d31a9dae1bc5/IQCpK38gmEvWT6F_Cso40Li-AXAKkSs-J67mCwll-C732pw?e=v4VVF5
С уважением,
Алексей М.
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3 days300 USD
308 3 days300 USDHello! With extensive experience in Kotlin/Spring Boot and reactive systems, I am ready to develop the backend core of Smart Mobility, handling POOL trips, real-time matching, chat, and secure trip tracking. My approach ensures clean architecture, concurrency safety, and step-by-step delivery of modules according to your technical requirements. Thank you.
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2 days300 USD
2227 5 1 2 days300 USDHello! I have reviewed your assignment and believe that I can successfully complete it. I would be happy to collaborate, please write to me personally for further details.
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