Md Ashfaq Salehin, Software Developer in London, United Kingdom
Md Ashfaq Salehin

Software Developer in London, United Kingdom

Member since October 31, 2018
Ashfaq is a full-stack developer focusing on Android development over the last few years. He is currently working at Meta Platforms Inc. as Software Engineer. His previous works include a self-ventured Android application built with NDK, which helps in audio editing and mixing. Apart from that, he has a couple of years of experience working in back-end technologies and distributed systems. Ashfaq enjoys working in complex and performance-intensive applications.
Md is now available for hire


  • Meta
    Android, Kotlin, Java
  • HelloFresh USA
    Android, Android SDK, Unit Testing, UI Testing, Continuous Integration (CI)
  • OPN
    Kotlin, Android SDK, User Permissions, Encryption, RxJava, Dagger 2, Hilt...



London, United Kingdom



Preferred Environment

IntelliJ, MacOS, Android Studio, Slack

The most amazing...

...project I've worked on is an audio recording, editing, and mixing application built using NDK, Kotlin, and several low-level C++ libraries, such as FFmpeg.


  • Software Engineer | Android

    2022 - PRESENT
    • Solved cross-organization problems in Facebook, WhatsApp, and Instagram applications.
    • Maintained relationships with stakeholders in Meta's partner companies, such as Google and Samsung.
    • Integrated and maintained third-party service implementations inside Facebook and WhatsApp.
    Technologies: Android, Kotlin, Java
  • Android Developer

    2021 - 2022
    HelloFresh USA
    • Designed and implemented multiple important features from scratch in a HelloFresh Android application.
    • Worked to find some complex bugs and fixed them in the application.
    • Implemented mocked UI tests for many old and new flows.
    • Participated in internal product design and scrum meetings.
    • Analyzed requirements and created Jira tasks and subtasks. Estimated efforts in the implementation of complex features.
    • Performed code review and hosted meetings in case of complex issues.
    • Conducted release testing for the teams to which I was assigned.
    Technologies: Android, Android SDK, Unit Testing, UI Testing, Continuous Integration (CI)
  • Android Developer

    2020 - 2021
    • Led, designed, and developed various Android applications and internal SDKs.
    • Developed a major part of the Toyota Wallet application.
    • Designed and developed internal SDKs for the company, such as a storage framework and user kit.
    Technologies: Kotlin, Android SDK, User Permissions, Encryption, RxJava, Dagger 2, Hilt, JUnit, React Native
  • Senior Software Engineer

    2019 - 2020
    • Worked in the flight post-booking system development team.
    • Implemented a system design that included back-end development with Scala and React for the front end.
    • Contributed significantly to the logging system by working with Hadoop and the ELK stack.
    Technologies: React, Java, Scala, Hadoop, Spark, GraphQL, Go, Jest, Next.js
  • System Developer

    2018 - 2019
    DIAKRIT International
    • Designed and developed various features in the company's order management system built with PHP.
    • Worked in the front-end shop website built with Vue.js and React.
    • Identified bugs, created bug tickets, and communicated with other teams to help with prioritization.
    Technologies: Vue, Laravel, JavaScript, PHP, React
  • Senior Full-stack Developer (Part-time)

    2017 - 2018
    • Worked with a price summarization system from millions of car sale records using Spark and MySQL.
    • Built widgets to display car price data aggregated and summarized using Spark.
    • Created various integration scripts for client companies using our services.
    • Developed custom data feeds for important clients.
    Technologies: JavaScript, PHP


  • Mixi — Audio Editor, Recorder, and Mixer

    This personal project is an Android application for recording, editing, and mixing audio files. A limited open-source version of this application is available here:

    Project Highlights:
    • This is an NDK-based project. Most of the operational parts of the project are done as native codes.
    • This project is built with Android architecture components, MVVM, LiveData, navigation, data binding, coroutines, and more.
    • Hilt is used as a DI framework.
    • RxJava and a reactive programming pattern are used to act against various view events.
    • Used Google Oboe as the audio streaming framework and FFmpeg for decoding and encoding audio.

  • Fast Mixer

    A heavy NDK-based Android application for recording, editing, and mixing audio.

    This project is done using the latest Android architecture components, MVVM, LiveData, navigation, data binding, coroutines, and more.

    Key Deliverables:
    • Used Hilt for dependency injection.
    • Used RxJava and a reactive programming pattern to act against various view events.
    • Designed some complex custom views doing heavy rendering jobs. Used RxJava observers heavily inside those views to react promptly against UI actions.
    • Performed all heavy computation and IO tasks in background threads (IO Dispatcher and Default Dispatcher).

    Most of the operational parts of the project are done as native codes. The solution is scalable and will allow many layers of further improvements without a significant structural refactor.
    The app uses FFmpeg for decoding audio and libsndfile to write into a WAV file. and ASAN and HWASAN to track memory leaks.

  • Toyota Wallet (Thailand)

    I developed this application as part of my job responsibilities while working at OPN. I built many core features of the application with native Kotlin MVVM architecture. and, as part of my job role, I owned some important features of this application.

  • VinAudit MarketValue

    This project was done using Spark, Hadoop, and Scala. This is a back-end service to calculate a summary of vehicle prices for a particular year, make, model, and trim. This deals with a huge amount of data. Each night it runs and calculates a summary of hundreds of millions of raw sales records and summarizes statistical information grouped by each year, make, model, and trim. As data can be too noisy, the system runs outlier detection on the rows to pre-filter out anomalies. It is a very dynamic back-end service. This is still under development.


  • Languages

    Kotlin, JavaScript, Java, PHP, Scala, C++, TypeScript, Java Persistence Query Language (JPQL), SQL, C, Java 11, GraphQL, Python, Go
  • Frameworks

    Android SDK, React Native, Spring Boot, Laravel, Hadoop, Spark, Dagger 2, Hibernate, JPA, Jest, Symfony, Eloquent, Spring, JUnit, Next.js
  • Libraries/APIs

    React, RxJava, REST APIs, Doctrine, Vue, Node.js
  • Tools

    Android NDK, Android Studio, Git, IntelliJ
  • Paradigms

    REST, Microservices, Scrum, Mobile Development, Unit Testing, Continuous Integration (CI), Object-relational Mapping (ORM), MapReduce
  • Platforms

    Linux, WordPress, Android, Amazon Web Services (AWS), MacOS
  • Storage

    MySQL, PostgreSQL, Relational Databases, MongoDB
  • Other

    Hilt, Full-stack, Mobile Apps, Payment APIs, Payment Gateways, UI Testing, Integration Testing, GitOps, Data Compression, Encryption, APIs


  • Bachelor of Science Degree in Electronics and Communication Engineering
    2009 - 2013
    Khulna University - Khulna, Bangladesh


  • Associate Android Developer
    APRIL 2021 - APRIL 2024
    Google Developers
  • CCA Cloudera Spark and Hadoop Developer
    APRIL 2020 - APRIL 2022
  • Application Security and Secure Coding Training In Scala
    MAY 2019 - MAY 2020
  • International English Language Testing System (IELTS)
    MAY 2013 - PRESENT
    British Council and Cambridge ESOL
  • Cisco Certified Network Associate
    NOVEMBER 2012 - NOVEMBER 2015
    Cisco System INC

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