Hysem is available for hire
Hire HysemHysem Saleem
Verified Expert in Engineering
Back-end Developer
Ernakulam, Kerala, India
Toptal member since March 8, 2022
Bio
Hysem is a seasoned back-end engineer with 8+ years of experience, skilled in Go, Java, and PHP. He has focused on developing scalable, well-tested, and extensively documented code throughout his career. Hysem enjoys working collaboratively but can also run projects independently.
Portfolio
MachineMax
Go, Google Cloud IoT Core, Google Cloud Platform (GCP), PostgreSQL, Redis...
Lariat Data, Inc.
Go, Python, Databases, APIs, Amazon Web Services (AWS), Java, Redis, Docker...
Ninjavan
Go, Apache Kafka, Java, Redis, MySQL, Docker, API Gateways, Back-end...
Experience
- Back-end - 7 years
- Redis - 6 years
- MySQL - 6 years
- Git - 6 years
- Docker - 6 years
- Go - 6 years
- Java - 4 years
- PostgreSQL - 3 years
Availability
Part-time
Preferred Environment
Ubuntu
The most amazing...
...code quality improvement I've done with a marketing app resulted in maintainable, bug-free, and efficient code.
Work Experience
Back-end Engineer
2022 - 2024
MachineMax
- Designed and implemented an in-house IoT Core service with the bare minimum requirements because Google Cloud IoT Core is being deprecated. Also implemented the client code for seamless integration with other services.
- Maintained and implemented features for the back-end services.
- Designed and reimplemented the existing application using the Actor Model (Go SDK for the Proto.Actor) for better scalability and maintenance.
Technologies: Go, Google Cloud IoT Core, Google Cloud Platform (GCP), PostgreSQL, Redis, Google Pub/Sub, Docker, Docker Compose, Message Queues, Microservices, GitHub, TypeScript, Unit Testing, Distributed Systems, Back-end Development, Debian, Linux, REST APIs, APIs, AWS Lambda, Lambda Functions, Google Cloud Functions, GitHub Actions, CI/CD Pipelines, Object-oriented Programming (OOP), HTTP, API Integration, Jira, Cloud Run, Google Cloud, Kubernetes, Internet of Things (IoT), Akka Actors, Actor Model, Protobuf, gRPC, Python, Google Kubernetes Engine (GKE), Helm
Back-end Developer
2023 - 2023
Lariat Data, Inc.
- Implemented and improved various endpoints as per the client's requirements and worked on several refactoring and code quality improvement tasks.
- Improved performance by storing frequently accessed response data in a Redis cache and retrieving it as needed. This reduced the number of database queries, which improved performance and scalability.
- Optimized the performance of endpoints by grouping multiple external network requests together and making them in a single batch. This reduced the number of network requests that were made, which improved performance.
- The aggregation logic was moved from the database query to the code because the aggregate function needed to be able to change depending on the specific data that was being aggregated. This made the aggregation process more flexible and efficient.
Technologies: Go, Python, Databases, APIs, Amazon Web Services (AWS), Java, Redis, Docker, Docker Compose, NoSQL, REST, JSON, Datadog, Unit Testing, Distributed Systems, Back-end Development, Debian, Linux, REST APIs, Object-oriented Programming (OOP), HTTP, API Integration
Senior Engineer
2022 - 2022
Ninjavan
- Contributed to the migration of a legacy core application written in Java into individual microservices using Go.
- Worked on several refactoring and code quality improvement tasks.
- Added integration test suite, which reduced developers' effort in verifying existing business logic during development.
Technologies: Go, Apache Kafka, Java, Redis, MySQL, Docker, API Gateways, Back-end, Test-driven Development (TDD), NoSQL, Integration Testing, Relational Databases, Message Queues, Microservices, Bitbucket, Unit Testing, Distributed Systems, Back-end Development, Debian, Linux, REST APIs, APIs, Object-oriented Programming (OOP), HTTP, API Integration, Jira
Back-end Developer
2022 - 2022
Lariat Data, Inc.
- Implemented and improved various endpoints as per the client's requirements and worked on several refactoring and code quality improvement tasks; this was done for a machine learning-based product.
- Developed an SQL query parser to validate it against a custom schema.
- Implemented a package for connecting to Python runtime from Go.
Technologies: Go, Databases, APIs, Amazon Web Services (AWS), Python, REST, API Gateways, Back-end, Test-driven Development (TDD), NoSQL, Relational Databases, Microservices, GitHub, Unit Testing, Distributed Systems, Back-end Development, Debian, Linux, REST APIs, Object-oriented Programming (OOP), HTTP, API Integration, Jira
Lead Engineer
2019 - 2022
QBurst
- Worked on several refactoring and code quality improvement tasks and reduced the boilerplate code required to write unit tests with the help of mock generation.
- Implemented several developer-friendly Go packages for the application code, unit, and integration tests.
- Contributed to the back-end services like APIs, scheduled jobs, and more.
Technologies: JavaScript, Git, React, PostgreSQL, Docker, Docker Compose, Elasticsearch, Redis, Go, Jenkins, SQL, REST, Databases, Amazon Web Services (AWS), API Gateways, Back-end, Node.js, Test-driven Development (TDD), NoSQL, Integration Testing, Relational Databases, MongoDB, Microservices, GitHub, Unit Testing, Distributed Systems, Back-end Development, Debian, Linux, REST APIs, APIs, Object-oriented Programming (OOP), HTTP, API Integration, Jira
Software Engineer
2016 - 2019
HifX
- Developed and maintained an SSO application back end and queue consumer service and developed a Java SDK for integration with the Android app.
- Contributed to a job portal project, including its role-based admin and separate APIs for recruiter and candidates.
- Worked on an event management platform's role-based admin and consumer API.
Technologies: PHP, Go, Java, AngularJS, Amazon Simple Queue Service (SQS), Amazon DynamoDB, MySQL, Redis, Elasticsearch, Git, SQL, REST, Databases, Spring Boot, Amazon Web Services (AWS), API Gateways, Back-end, Node.js, Test-driven Development (TDD), NoSQL, Relational Databases, Message Queues, Microservices, GitLab, Unit Testing, Distributed Systems, Back-end Development, Debian, Linux, REST APIs, APIs, AWS Lambda, Lambda Functions, Google Cloud Functions, Spring, Object-oriented Programming (OOP), HTTP, API Integration, Jira, Apache Tomcat, IntelliJ IDEA, NetBeans
Experience
Marketing App for a Client in the Textiles Industry
I contributed to developing back-end APIs, scheduled jobs, and role-based admins using Go, PostgreSQL, React, AWS S3, Google Vision, and more.
This app allows users and staff to post pictures of outfits, and these images will be analyzed using Google Vision. Responses will be used to provide recommendations to other users.
This app allows users and staff to post pictures of outfits, and these images will be analyzed using Google Vision. Responses will be used to provide recommendations to other users.
Blockchain Platform as a Service
This project dealt with setting up the network and associated requirements for blockchain.
I contributed to the user microservice responsible for authentication and access management. Also, I improved code coverage and added integration tests.
I contributed to the user microservice responsible for authentication and access management. Also, I improved code coverage and added integration tests.
Single Sign-on Application
This project allowed single sign-on for clients' applications.
I contributed to this application's front end, back end, and other scheduled jobs. I was part of a significant feature change that allowed the client to capture users' mobile numbers on login for the client apps that require both of these data. I also developed a Java SDK for seamless integration with Android apps.
I contributed to this application's front end, back end, and other scheduled jobs. I was part of a significant feature change that allowed the client to capture users' mobile numbers on login for the client apps that require both of these data. I also developed a Java SDK for seamless integration with Android apps.
Event Management Application
The client needed to create an app for organizing events where the attendees could register before the event. They would receive a QR code in the mail to show at the venue to enter the event. Once they register, users can log in using a mobile app to ask questions during the event, and a moderator can pick from those questions and discuss them with the speakers.
Education
2010 - 2014
Bachelor's Degree in Electrical and Electronics Engineering
Mahatma Gandhi University - Kottayam, Kerala, India
Skills
Libraries/APIs
Node.js, REST APIs, React, jQuery, Protobuf
Tools
Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (SNS), Apache Tomcat, IntelliJ IDEA, Git, Docker Compose, Jira, Jenkins, Amazon Simple Email Service (SES), GitHub, Bitbucket, GitLab, Google Kubernetes Engine (GKE), Helm
Languages
Go, Java, SQL, JavaScript, Python, TypeScript, PHP, C, Embedded C, HTML, CSS, SCSS
Frameworks
Spring, AngularJS, Apache Camel, gRPC, Spring Boot
Paradigms
Test-driven Development (TDD), Unit Testing, Object-oriented Programming (OOP), Microservices, REST, Actor Model
Platforms
Debian, Linux, AWS Lambda, Cloud Run, NetBeans, Docker, Ubuntu, Amazon Web Services (AWS), Google Cloud Platform (GCP), Kubernetes, Apache Kafka, Google Cloud IoT Core
Storage
Relational Databases, Google Cloud, Redis, PostgreSQL, MySQL, NoSQL, Elasticsearch, Amazon S3 (AWS S3), Amazon DynamoDB, Databases, MongoDB, JSON, Datadog
Other
APIs, Back-end, Integration Testing, Back-end Development, Lambda Functions, Google Cloud Functions, HTTP, API Integration, API Gateways, Message Queues, Distributed Systems, GitHub Actions, CI/CD Pipelines, NATS, Google Pub/Sub, Online Payments, Internet of Things (IoT), Akka Actors
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