Nikita is currently unavailable
Nikita Kraev
Verified Expert in Engineering
Mobile Developer
Amsterdam, Netherlands
Toptal member since August 25, 2020
Bio
Nikita is a skilled software engineer based in Amsterdam. His expertise spans various technologies from mobile (Kotlin, Android, React Native, and Flutter) to server-side, leveraging Scala and PHP/Hack. He can also lead through mentoring, optimizing codebases, and enhancing user experiences across different projects. With a bachelor's in computer science and a commitment to continuous improvement, Nikita is certainly a valuable asset to any tech team.
Portfolio
Hopper
Scala, gRPC, Protobuf, Android, Server-side Rendering (SSR)
Meta
Android, React Native
Voi Technology AB
CircleCI, Mapbox, Dependency Injection, Coroutines, Kotlin, Android
Experience
- Android - 10 years
- Kotlin - 10 years
- Firebase - 7 years
- React Native - 5 years
- GraphQL - 5 years
- RxJava 2 - 4 years
- Flutter - 3 years
- Coroutines - 2 years
Work Experience
Software Engineer
2023 - PRESENT
Hopper
- Implemented a customer experience refund flow using server-side rendering and custom framework, resulting in 90% satisfaction rate for flights cancelation flow.
- Built a ChatGPT-powered customer assistant that deep links into various surfaces in the app, reducing customer support reachouts by 62%.
- Leveraged a microservices architecture to remove price conversion from GRPC request payload, resulting in 150 msec/12% improvement in the booking flows.
Technologies: Scala, gRPC, Protobuf, Android, Server-side Rendering (SSR)
Software Engineer
2020 - 2023
Meta
- Mentored three engineers on two different projects, enabling them to deliver their first features in less than three months after joining the team.
- Improved the ad campaign editing flow, resulting in a 90% faster experience, from 1.5 sec to 150 msec per editing attempt.
- Interviewed more than 50 candidates, resulting in three hires to the team.
- Facilitated a breakdown of the machine learning smart gallery prototype into achievable, concrete milestones.
- Reduced new feature implementation times and code duplication for internal developers by unifying the gallery rendering pipeline and making it reusable.
- Built support for multi-device viewing and implemented Ray-Ban Stories smart glasses media cropping and compression to make images shareable on Instagram and Facebook.
- Leveled up developers in the team by holding Kotlin best practices workshops and presentations.
Technologies: Android, React Native
Senior Android Developer
2019 - 2020
Voi Technology AB
- Migrated the legacy codebase into modern and coroutine-based reactive Kotlin code. The project took three months to develop but in the end, it allowed us to iterate 2.4x times faster than before (about 3.1W vs 7.66W before per feature).
- Developed a new Mapbox-based map layer, which rendered independently from server responses and improved our TTI (time to interact) by more than 350 milliseconds.
- Researched instruments and options and picked Flutter when creating a new employee application. That allowed me to iterate faster while being alone, compared to two other developers who worked together on the same project.
- Improved Agile processes in the team, resulting in a reduction of unnecessary meetings, better product owner awareness of progress, and new tool enablement for project scope visibility.
- Helped iOS engineers set up continuous integration and continuous delivery using CircleCI.
Technologies: CircleCI, Mapbox, Dependency Injection, Coroutines, Kotlin, Android
Android Developer
2018 - 2019
Rebtel Networks AB
- Led a development team of three Android engineers when creating a brand-new fintech banking app from scratch in very strict deadlines.
- Introduced Kotlin to the codebase by writing about 400 tests following the language's best practices and showcased them to the team.
- Created a feature toggle mechanism from scratch, bundling it into a legacy app that allowed us to remove dead code and cancel experiments 7x faster (3D vs 3W before).
- Led Material Design discussions with the lead designer which helped us to build a visually stunning custom application while keeping the native Android UX.
Technologies: Material Design, Firebase, Reactive Streams, Dagger 2, RoomDB, Code Architecture, Kotlin, RxJava 2, Android
Lead Android Developer
2017 - 2019
Urbest
- Migrated an old and slow legacy Java app into Kotlin, reducing the lines of code (LOC) from 58,000 to just 19,000.
- Introduced dynamic module loading into native Android by splitting DEX files and ordering them by the module requirements. That improved our TTI (time to interact) by more than 1,300 milliseconds.
- Initiated the research and A/B testing on a small number of users to drive UX and UI discussions by metrics without being subjective.
- Participated in the launch of a React Native app rewrite (ClojureScript and React Native) while maintaining, extending, and bug-fixing a Kotlin version in parallel.
Technologies: ClojureScript, Clojure, React Native, RxJava 2, GraphQL, Kotlin, Android
Project History
Voi Scooters App
https://play.google.com/store/apps/details?id=io.voiapp.voi&hl=en&gl=US&pli=1A Kotlin and coroutines-based application for the Stockholm startup Voi. I was one of the lead Android developers and participated in the app re-architecture and unidirectional data flow. That allowed us to create new features much faster, which is essential for a startup.
Majority
A Kotlin-based app for the Swedish company Rebtel. This is a digital banking application specifically targeted at immigrants. Everything was created with a very tight deadline. But we did impossible, and with only three Android developers, we launched this fresh-looking and feature-rich application in just six months!
Meta Ads Manager
https://play.google.com/store/apps/details?id=com.facebook.adsmanager&hl=en&gl=USOne of the biggest React Native apps in the world, directly supported and seen as a playground for the React Native team @ Meta itself.
I was one of the lead developers, doing the redesign of the app and bringing new and shiny features, including using the internal company framework for faster ad editing.
I was one of the lead developers, doing the redesign of the app and bringing new and shiny features, including using the internal company framework for faster ad editing.
Meta View app
https://play.google.com/store/apps/details?id=com.facebook.stella&hl=en&gl=USA native Android application to control and download media from Ray-Ban Stories™ and Ray-Ban Meta™ smart glasses.
I was in charge of designing and implementing the multi-device faceted architecture, bringing all my experience for ultra-fast scrolling and smooth transitions when downloading and viewing media.
I was in charge of designing and implementing the multi-device faceted architecture, bringing all my experience for ultra-fast scrolling and smooth transitions when downloading and viewing media.
Hopper app
https://play.google.com/store/apps/details?id=com.hopper.mountainview.play&hl=en&gl=USA semi-native app that utilizes server-side rendering (SSR). I was part of the customer experience (CX) team, which builds and maintains support flows for customers.
One of the biggest achievements here is building a ChatGPT-powered smart travel assistant using SSR and a minimum amount of native code that allows you to book travel on the app.
One of the biggest achievements here is building a ChatGPT-powered smart travel assistant using SSR and a minimum amount of native code that allows you to book travel on the app.
Education
2015 - 2017
Bachelor's Degree in Computer Science
Innopolis University - Innopolis, Russia
Skills
Libraries/APIs
RxJava 2, Protobuf
Tools
Flow, Android Studio, IntelliJ IDEA, CircleCI
Languages
Kotlin, GraphQL, JavaScript, TypeScript, Clojure, Scala
Frameworks
React Native, Flutter, Dagger 2, ClojureScript, gRPC, Redux
Platforms
Android, Firebase, Visual Studio Code (VS Code), Linux, Mapbox, MacOS
Storage
RoomDB
Paradigms
Dependency Injection, Model View ViewModel (MVVM)
Other
Coroutines, Code Architecture, Reactive Streams, Material Design, Server-side Rendering (SSR), Architecture
Collaboration That Works
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
1
Share your needs
Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2
Choose your talent
Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3
Start your risk-free talent trial
Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.
Top talent is in high demand.
Start hiring