Abhi Tyagi, Developer in Bengaluru, Karnataka, India
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Abhi Tyagi

Verified Expert  in Engineering

Back-end Developer

Location
Bengaluru, Karnataka, India
Toptal Member Since
July 20, 2020

Abhi is a highly skilled Node.js and PostgreSQL developer with 12+ years of experience in software engineering. He started his career at Nokia and then moved into startup environments. Abhi has led several teams, set technology strategies and rolled up his sleeves to deliver the back and front end for a wide variety of applications. He excels in end-to-end product development, ensuring great user experience through high-quality products, and he is comfortable working in teams of any size.

Back-endFull-stackFull-stack DevelopmentREST APIsNode.jsExpress.jsPostgreSQLRedisAPI ArchitectureAmazon Web Services (AWS)Amazon EC2TypeScriptData ScrapingInternet of Things (IoT)iOSiBeacon

Portfolio

Nestegg UK (via Toptal)
Node.js, Amazon RDS, PostgreSQL, APIs, Architecture, Credit Unions...
Deol Data, Veersky
Architecture, GPS, Core Location, Amazon Web Services (AWS), JavaScript...
Bounce
Architecture, GPS, JavaScript, Git, TypeScript, REST, RESTful Development...

Experience

Back-end - 6 yearsPostgreSQL - 6 yearsNode.js - 6 yearsExpress.js - 6 yearsRedis - 5 yearsAPI Architecture - 5 yearsAmazon Web Services (AWS) - 5 yearsTypeScript - 3 years

Availability

Part-time

Preferred Environment

Slack, Docker, Visual Studio Code (VS Code), Linux, MacOS, Postman

The most amazing...

...product I've developed was a complete social network for mentors and aspiring entrepreneurs in the African subcontinent.

Work Experience

Senior Back-end Node.js Developer

2021 - 2022
Nestegg UK (via Toptal)
  • Handled the architecture and development of all new APIs and features at Nestegg—a SaaS platform for Credit Unions to process loan applications and automate decisions across the UK.
  • Designed the architecture and single-handedly developed the decision-making engine from the ground up. This engine automates the assessment of credit risk and the processing of loan applications.
  • Constructed a financial health monitoring system (for end users) based on open banking and credit bureau data.
  • Created the DB architecture and developed several consumer-facing APIs and features such as Lender rule management, monthly financial health, report exports, etc.
  • Built a Stripe-like webhook calling system from the ground up.
  • Integrated TransUnion APIs for Credit data and TrueLayer APIs for Open Banking.
  • Helped the company migrate their entire systems from Heroku to AWS, RDS, Beanstalk, Load Balancer, and CodePipeline with proper planning and execution.
Technologies: Node.js, Amazon RDS, PostgreSQL, APIs, Architecture, Credit Unions, Credit Scores, Credit Risk, AWS CodePipeline, GitHub, Heroku, Amazon EC2, Amazon Web Services (AWS), Express.js, Back-end, API Architecture, TrueLayer API, JSON Web Tokens (JWT), API Integration, DevOps

Senior Full-stack Node.js and iOS Developer

2020 - 2020
Deol Data, Veersky
  • Designed and developed the architecture for the entire back end for the social and retail discovery platform, using Node.js, Express.js, and PostgreSQL, and deployed on AWS Elastic Beanstalk and RDS.
  • Developed a video live streaming back end, using nginx-rtmp, with RTMP streams as input from the iOS app and multiple-resolution HLS as the output, also known as adaptive bitrate HLS streaming.
  • Implemented location-based discovery using PostGIS geolocation queries on the back end and interactive Google Maps on the iOS side with popover information banners that could display social information, images, and video.
  • Implemented high-performance search features using PostgreSQL full-text search, enabling rich search functionality over social data, keywords, and interests.
  • Implemented a payment system for the platform, using Stripe and TaxJar APIs for the merchants and in-app purchases for premium subscriptions. Used Stripe Connect to enable payouts to the merchants.
  • Implemented phone number sign-up and verification using Twilio API.
Technologies: Architecture, GPS, Core Location, Amazon Web Services (AWS), JavaScript, In-app Purchases, Maps, Twilio API, HTTP Live Streaming (HLS), LiveStream, TaxJar API, Mobile Payments, Stripe API, MikroORM, TypeScript, Swift, iOS, PostGIS, PostgreSQL, Express.js, Node.js, Amazon S3 (AWS S3), Back-end, Redis, API Architecture, Technical Leadership, JSON Web Tokens (JWT), API Integration, Full-stack, Full-stack Development, DevOps, WebSockets, Socket.IO, Stripe, AWS Lambda, Firebase

Back-end Engineering Manager

2019 - 2020
Bounce
  • Managed and participated in the back-end team responsible for payments, new user onboarding, and new city launches.
  • Designed and led the team to develop a new payment system, integrating with country's leading payment providers.
  • Redesigned the architecture of the automated document verification system to handle the increased volumes and new document types.
  • Led the back-end development team to build an entirely new back end for a new business model the company implemented for small cities and towns.
  • Deployed the databases, microservices, and back end on AWS (RDS, EC2, ElastiCache, and SQS).
Technologies: Architecture, GPS, JavaScript, Git, TypeScript, REST, RESTful Development, Amazon EC2, SQL, API Architecture, REST APIs, Amazon Web Services (AWS), Passport.js, Redis, PostgreSQL, Express.js, Node.js, Amazon S3 (AWS S3), Back-end, Technical Leadership, API Integration, React, Internet of Things (IoT), Microservices

Founder and Engineer

2019 - 2020
RankUp App
  • Built an iOS analytics application that developers and development studios use to track the performance of their own apps on the App Store.
  • Developed a highly responsive and interactive homepage using UICollectionView and asynchronous data fetching and processing using dispatch queues.
  • Created a beautiful monthly charts feature using the iOS Charts library.
  • Developed a high-performance back end using Node.js, Express.js, and PostgreSQL, and deployed it on Docker containers on DigitalOcean.
  • Built a time series back end, using TimescaleDB to store and deliver monthly statistics.
  • Implemented a monthly subscription using Apple's auto‑renewable subscriptions (in-app purchase) and server-side receipt validation.
Technologies: Architecture, JavaScript, In-app Purchases, Express.js, Swift, REST, RESTful Development, SQL, Xcode, API Architecture, REST APIs, TypeScript, PostgreSQL, Node.js, iOS, Swift 4, Back-end, JSON Web Tokens (JWT), API Integration, Data Scraping, Full-stack, Full-stack Development, MySQL

Mobile and Back-end Engineering Manager

2017 - 2018
Neva Innovation Labs
  • Set the technical vision for the company by designing the architecture and technology stack for its products (Node.js, Express, MongoDB, Postgres, ThingsBoard, RabbitMQ, and Python Celery).
  • Led the entire technology team at the company and served as a hands-on engineering manager for the back-end and mobile teams that developed and delivered several applications.
  • Developed a driving behavior analysis app to deliver analytics on the quality of driving by drivers. The app collected data from smartphone sensors (accelerometer, gyroscope, and GPS) and sent it to the back end in an efficient manner.
  • Built a robust data ingestion back end to receive high volumes of data coming from smartphone sensors then process and transfer it to the machine learning (ML) back end.
  • Converted the Python ML scripts from the data science team to a highly parallel and highly available ML back end using message queues and several worker processes (RabbitMQ and Python Celery).
  • Designed and developed the entire back end following best principles and REST architecture.
  • Created and implemented algorithms critical to the company's business model, such as crash detection and scoring algorithms for driving parameters.
Technologies: Architecture, GPS, Git, REST, Amazon EC2, SQL, API Architecture, REST APIs, Amazon Web Services (AWS), RabbitMQ, Redis, PostgreSQL, MongoDB, Express.js, Node.js, Python, Flask, Back-end, Technical Leadership, JSON Web Tokens (JWT), Internet of Things (IoT), ThingsBoard, Full-stack, Full-stack Development, MySQL

iOS Tech Lead

2015 - 2017
Neva Innovation Labs
  • Designed the architecture and developed several iOS apps as a lead of the entire iOS team.
  • Built an app to deliver IoT-enabled managed services in large facilities such as hospitals and manufacturing plants. The app delivers a seamless task-management experience to staff and managers by using iBeacons and indoor location tracking.
  • Developed wrapper classes for widely used libraries (e.g., Alamofire) to deliver a seamless networking experience when offline or in low bandwidth areas.
  • Built an app to perform live image recognition on video feeds from phone cameras, using a TensorFlow iOS SDK.
  • Helped the company adopt Apple design guidelines and security best practices such as using Keychain Access to store credentials and certificate pinning for critical applications.
Technologies: Architecture, GPS, Git, Xcode, iBeacon, Core Location, Objective-C, Swift, Technical Leadership, JSON Web Tokens (JWT), ThingsBoard

R&D Engineer

2010 - 2012
Nokia
  • Participated in the team that developed the Nokia Servicing Gateway (SGW) as an R&D engineer within software development.
  • Leveraged my core area of expertise—telecom signaling protocols.
  • Rewrote a module that processed incoming messages, permanently eliminating a family of recurring bugs.
Technologies: Linux, C++, C

Nestegg

https://nestegg.ai/
Nestegg is a SaaS platform for Credit Unions to process loan applications and automate decisions across the UK. I was in charge of the architecture and development of all new features and APIs at Nestegg.

Bounce - Scooter Rentals

https://apps.apple.com/app/id1191889101
Bounce is India's largest urban mobility solution in the two-wheeler rental space. The app has 300,000+ active users who complete 100,000 rides per day.

I was the back-end engineering manager. Being a hands-on person, I led the team, and I was involved in developing several core modules, including the payments system and the automated document verification system.

RankUp App

RankUp is a Swift-based analytics app used by app developers, publishers, and marketers to monitor the performance of any app on the App Store. In addition to originating the concept, I developed the iOS app and the back end. It was published on the App Store in 2019 and it's still live with around 1,000 loyal users.

Jido Sense

https://apps.apple.com/us/app/jido-sense/id1472967606
The app allows you to analyze your driving behavior based on data from sensors in your smartphone, combined with in-house driving score and crash detection algorithms. The app predicts the vehicle's health and helps users become better drivers.

Languages

TypeScript, JavaScript, Swift, Swift 4, SQL, Python, Objective-C, C, C++

Frameworks

Express.js, Core Location, JSON Web Tokens (JWT), Flask, Jest

Libraries/APIs

Node.js, REST APIs, Stripe, React, Socket.IO, Passport.js, Stripe API, Twilio API

Tools

Git, Xcode, RabbitMQ, Apache, GIS, Postman, GitHub

Paradigms

API Architecture, RESTful Development, REST, Microservices, DevOps

Platforms

Docker, Amazon Web Services (AWS), Amazon EC2, MacOS, iOS, AWS Lambda, Visual Studio Code (VS Code), Linux, Firebase, Heroku

Storage

PostgreSQL, Redis, NoSQL, MySQL, PostGIS, Amazon S3 (AWS S3), MongoDB, CouchDB, Amazon DynamoDB

Other

Code Architecture, Technical Leadership, Back-end, APIs, GPS, Architecture, API Integration, ThingsBoard, Full-stack, Full-stack Development, MikroORM, In-app Purchases, TrueLayer API, Internet of Things (IoT), Data Scraping, WebSockets, iBeacon, Push Notifications, Mobile Payments, TaxJar API, LiveStream, HTTP Live Streaming (HLS), Maps, Amazon RDS, Credit Unions, Credit Scores, Credit Risk, AWS CodePipeline

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