David is available for hire
Hire DavidDavid Grigorian
Verified Expert in Engineering
Software Engineer and Developer
Boston, MA, United States
Toptal member since July 4, 2024
Bio
David is a seasoned full-stack software engineer specializing in back-end development. As the lead engineer, he's led the development of a truck and load scheduling platform now used by the largest US trucking company. As the back-end architect and co-founder of ParcelRobin, David has driven the startup to six-figure annual revenue with over a thousand loyal users. He delivers impactful solutions, leveraging his extensive experience to innovate and optimize software development processes.
Portfolio
Routary
C#, .NET 8, Redis Cache, PostgreSQL, Amazon Simple Queue Service (SQS), Stripe...
Dept Agency
REST, GraphQL, .NET 6, .NET Framework, Elasticsearch, Vue 3, Jenkins...
ParcelRobin
C#, .NET 7, MySQL, RabbitMQ, Redis Cache, Stripe, EasyPost, Git, GitHub Actions...
Experience
Availability
Part-time
Preferred Environment
Windows, Visual Studio, Visual Studio Code (VS Code), WebStorm, Linux, Azure Data Studio, SQL Server 2016, MySQL Workbench, pgAdmin, Postman
The most amazing...
...work: I built a shipping label aggregator with 1,000+ users and $100,000+ annual revenue, showcasing my back-end expertise and passion for impactful solutions.
Work Experience
Co-founder | Back-end Architect
2023 - PRESENT
Routary
- Co-founded and served as the back-end architect, developing algorithms for dynamic route optimization and enhancing route precision by incorporating live traffic data, tolls, route matrices, and Google OR-Tools to solve complex routing problems.
- Designed and maintained a robust C# .NET 8 Web API that supports real-time data processing, integrating seamlessly with Google routes and Geocoding APIs, resulting in more accurate and efficient route calculations.
- Managed a complex PostgreSQL database with geographic and logistical data, optimizing queries to reduce latency and improve response times, leading to faster and more reliable route computations.
- Improved system throughput by 35% by implementing Redis cache and multithreading and efficiently handled webhooks using Amazon Simple Queue Service (SQS), significantly enhancing overall system performance.
- Streamlined the billing process and improved subscription management by integrating the Stripe API, enhancing user satisfaction and operational efficiency.
- Increased email campaign engagement by 17% by developing customizable email templates for Mailgun using the Handlebars framework, resulting in higher user interaction and response rates.
- Utilized OpenAI for image processing and address parsing, improving data accuracy and operational efficiency by 25%, contributing to better service delivery and customer satisfaction.
- Achieved growth with over 3,000 subscribers, 800 of which are paid subscribers, reflecting the platform's value and effectiveness.
Technologies: C#, .NET 8, Redis Cache, PostgreSQL, Amazon Simple Queue Service (SQS), Stripe, Google API, Git, GitHub Actions, .NET, Redis, Multithreading, Google APIs, Google Routes API, Google Geocoding API, Mailgun, Stripe API, Back-end, GitHub, Linux, API Architecture, REST, Ubuntu, .NET Core, Webhooks, DigitalOcean, Back-end Development, Visual Studio 2022, Handlebars, WebStorm, REST APIs, JSON, Complex SQL Queries, Swagger, API Documentation, Database Design, Relational Database Design, YAML, Google Workspace, Remote Work, OpenAI, OR-Tools, Architecture, APIs, Engineering, Google Docs, Message Queues, Software Architecture, System Design, API Integration, Startups, Databases, Software as a Service (SaaS), C#.NET, Payment APIs, Object-oriented Programming (OOP), Integration, API Development, PL/SQL, API Design
Senior Software Engineer
2021 - 2024
Dept Agency
- Led development teams of up to seven people, overseeing the design and development of REST APIs using C# .NET 6, .NET Core, and the .NET Framework, resulting in highly efficient and scalable back-end systems.
- Enhanced data query flexibility and improved user experience by implementing GraphQL endpoints, leading to more responsive and user-friendly applications.
- Optimized search capabilities and database performance by leveraging Elasticsearch and PostgreSQL, significantly reducing data retrieval times.
- Mastered Vue and the PrimeVue component library rapidly, leading to a 20% increase in front-end development speed and delivering a more responsive user interface for clients.
- Migrated existing pipelines from Jenkins to AWS CodePipeline successfully, increasing CI/CD process efficiency and reducing deployment times by 30%.
- Automated pipeline build processes by crafting YAML files and Dockerfiles, executed through AWS CodePipeline, streamlining the development workflow.
- Utilized various AWS tools to monitor builds and effectively address emerging issues, ensuring continuous integration and deployment without significant downtime.
- Collaborated closely with product managers and stakeholders, ensuring alignment between development efforts and business objectives, resulting in successful project deliveries.
- Contributed to iterative development and continuous improvement by working on teams using Agile or Kanban methodologies, enhancing team productivity and project outcomes.
- Developed multiple REST APIs using .NET Core and the .NET Framework, improving integration and functionality across various projects.
Technologies: REST, GraphQL, .NET 6, .NET Framework, Elasticsearch, Vue 3, Jenkins, AWS CodePipeline, AWS CloudFormation, C#, PostgreSQL, Git, Redis Cache, Bitbucket, Jira, Contentful, Apache Kafka, .NET, Amazon Web Services (AWS), .NET Core, REST APIs, GraphQL Federation, Vue, Jenkins Pipeline, YAML, Docker, Front-end, Back-end, User Experience (UX), GitHub, Bitbucket API, Agile, Kanban, Slack, Microsoft Teams, Zoom, Google Workspace, Team Leadership, Cross-functional Collaboration, Redis, Full-stack, Back-end Development, API Architecture, Azure DevOps, Back-end APIs, Back-end Architecture, JavaScript, Remote Work, Amazon WorkSpaces, PrimeVue, Visual Studio 2019, Visual Studio 2022, Visual Studio Code (VS Code), WebStorm, xUnit, NUnit, JSON, Mentorship, Mentorship & Coaching, HTML, CSS, Complex SQL Queries, API Documentation, Swagger, Database Design, Relational Database Design, Architecture, APIs, Engineering, Google Docs, Message Queues, Software Architecture, System Design, Agile Software Development, API Integration, Full-stack Development, Databases, Software as a Service (SaaS), C#.NET, Microsoft Azure, CI/CD Pipelines, Object-oriented Programming (OOP), Technical Leadership, Azure Functions, Content Management Systems (CMS), Integration, API Development, PL/SQL, API Design
Co-founder | Lead Back-end Engineer
2019 - 2023
ParcelRobin
- Co-founded and directed ParcelRobin, a shipping label aggregator platform, achieving significant cost savings for users through accessible, volume-based corporate discounts on shipment label rates.
- Built a platform serving over 1,000 returning customers and generating over $100,000 in annual recurring revenue.
- Architected and developed high-performance APIs using C# .NET 7, enhancing system efficiency and reliability.
- Spearheaded the architectural design and development of the MySQL database, ensuring robust data management and integrity.
- Improved message processing reliability by employing RabbitMQ for efficient 3rd-party webhook message queuing and handling.
- Enhanced application performance and scalability by implementing Redis cache, resulting in faster response times and increased throughput.
- Optimized user experience and functionality by collaborating with EasyPost for label management, streamlining the purchase of shipping labels, and increasing transaction success rates.
- Ensured secure and seamless transactions by integrating with Stripe APIs to handle customer payments, reducing payment processing errors.
- Automated document management tasks by developing a DigitalOcean function using Python to merge and upload PDF files, saving database space and improving retrieval and processing efficiency.
- Enhanced communication efficiency by creating customizable email templates for Mailgun using the Handlebars framework, increasing email engagement rates by 10%.
Technologies: C#, .NET 7, MySQL, RabbitMQ, Redis Cache, Stripe, EasyPost, Git, GitHub Actions, .NET, .NET Core, GitHub, Slack, Stripe API, Mailgun, Multithreading, REST, API Architecture, Redis, Back-end, Linux, Ubuntu, Webhooks, MySQL Workbench, DigitalOcean, Python, Back-end Development, Handlebars, Visual Studio 2022, Visual Studio 2019, WebStorm, Complex SQL Queries, API Documentation, Swagger, Database Design, Relational Database Design, YAML, Remote Work, DigitalOcean API, Architecture, APIs, Engineering, Google Docs, Message Queues, Software Architecture, System Design, API Integration, Startups, Databases, Software as a Service (SaaS), C#.NET, Payment APIs, Object-oriented Programming (OOP), Integration, API Development, PL/SQL, API Design
Senior Software Engineer
2019 - 2021
Citrix
- Collaborated within SAFe Agile teams, utilizing Bitbucket for source control and employing Jira for project management, which improved project tracking and team collaboration.
- Developed and enhanced features in C# for a Citrix application layering product, contributing to improved functionality and user experience.
- Developed and enhanced features on the Enterprise Layer Manager (ELM) using Aurelia, a JavaScript framework, resulting in a more intuitive and responsive user interface.
- Created TypeScript cloud connectors for Azure, Google Cloud Platform (GCP), and VMware vSphere platforms, enabling seamless cloud integration and improved system interoperability.
- Maintained code quality through unit testing, using NUnit for C# and Sinon for TypeScript, achieving high code coverage and ensuring reliable software performance.
- Developed advanced PowerShell scripts for task automation, reducing manual efforts and increasing operational efficiency by 50%.
- Oversaw the transition from Bamboo to Jenkins, writing advanced Jenkins pipeline code with Groovy, which streamlined the CI/CD process and reduced deployment times by 12%.
- Managed the Enterprise Layer Manager (ELM) on CentOS Linux, ensuring system stability and performance.
- Utilized both .NET Core and the .NET Framework for various projects, enhancing application performance and flexibility.
- Mentored junior engineers on the team, fostering skill development and knowledge sharing.
Technologies: Scaled Agile Framework (SAFe), Bitbucket, Jira, C#, Citrix XenApp, TypeScript, Azure, Google Cloud Platform (GCP), VMware vSphere, Windows PowerShell, NUnit, Sinon.JS, Bamboo, Jenkins, CentOS, .NET Core, MySQL, Aurelia, .NET, Angular, Team Leadership, Cross-functional Collaboration, Zoom, Microsoft Teams, Slack, VMware vSphere HA, Google Cloud, Google Cloud API, TypeScript 3, JavaScript, Linux, Windows, .NET Framework, Visual Studio 2019, Visual Studio Code (VS Code), Angular 6, Mentorship, Mentorship & Coaching, Google APIs, Agile, Remote Work, Azure CLI, APIs, Engineering, System Design, Agile Software Development, API Integration, Full-stack Development, Web Development, Databases, C#.NET, Microsoft Azure, CI/CD Pipelines, Object-oriented Programming (OOP), Technical Leadership, Integration, API Development, PL/SQL, API Design
Senior Software Engineer
2013 - 2019
NutriSavings
- Designed and updated website UI and admin pages using C#, ASP.NET, CSS, and JQuery, enhancing user experience and interface responsiveness. The application was hosted in IIS.
- Spearheaded the ground-up development of a new application using Angular 6, delivering a modern and efficient front-end solution and increasing user engagement by over 50%.
- Led the migration from on-premise servers to AWS and Azure, optimizing scalability and performance, resulting in a 25% increase in system reliability.
- Created REST APIs using .NET Core 2 and SQL Server 2008 R2, facilitating seamless data integration and improved system functionality.
- Worked with Entity Framework and also used stored procedures, views, and functions for SQL queries and data manipulation.
- Automated the entire build process with Jenkins, starting with a custom C# application, which streamlined the CI/CD pipeline and reduced deployment times by 80%.
- Employed Kentico CMS for efficient site management and multilingual display, improving content management and user engagement.
- Implemented quality assurance through unit tests using NUnit, ensuring high code quality and reliability.
- Provided leadership and mentorship to interns and junior developers, fostering skill development and enhancing team productivity.
Technologies: Microsoft SQL Server, Kentico, CSS, C#, Git, TortoiseSVN, ASP.NET, jQuery, Jenkins, .NET Core 2, .NET Framework, NUnit, .NET, Angular, Angular 6, Visual Studio 2017, Visual Studio 2010, SQL Server 2008 R2, Visual Studio Code (VS Code), WebStorm, Team Leadership, .NET Core, Slack, Agile, Full-stack, API Architecture, Front-end, Front-end Architecture, Back-end, Back-end APIs, Back-end Architecture, REST, REST APIs, JSON, Leadership, Mentorship, HTML, Jenkins Pipeline, Back-end Development, Front-end Development, SQL, TortoiseCVS, GitHub, Stripe API, Bitbucket, Mentorship & Coaching, Cross-functional Collaboration, SQL Stored Procedures, SQL Functions, Complex SQL Queries, SQL Views, Database Design, Relational Database Design, User Experience (UX), Bitbucket API, SQL Server 2016, Architecture, APIs, Engineering, Azure, Software Architecture, System Design, Entity Framework, IIS, Web Server (IIS), Agile Software Development, Startups, Full-stack Development, Web Development, Databases, C#.NET, CI/CD Pipelines, Object-oriented Programming (OOP), Technical Leadership, Content Management Systems (CMS), Integration, API Development, PL/SQL, API Design, ASP.NET Web Forms
Software Developer Consultant
2012 - 2013
Freelance Client
- Developed and maintained client applications utilizing C#, ASP.NET, and VB.NET.
- Designed and implemented Windows services using C#.
- Developed and managed SQL Server Reporting Services (SSRS) reports, complex SQL queries, views, and stored procedures.
- Conducted client meetings to elicit and document software requirements and specifications.
Technologies: C#, ASP.NET, VB.NET, SSRS Reports, Microsoft SQL Server, SQL, .NET, WordPress, Windows Services, SQL Server Reporting Services (SSRS), Visual Studio 2010, Complex SQL Queries, SQL Server 2008 R2, Microsoft Team Foundation Server, TFS, SQL Stored Procedures, SQL Views, API Documentation, Cross-departmental Collaboration, Cross-functional Collaboration, Database Design, Relational Database Design, Engineering, Full-stack Development, Databases, C#.NET, Object-oriented Programming (OOP), PL/SQL, ASP.NET Web Forms
Software Developer
2012 - 2012
Patriot Properties
- Introduced new features and improvements to AssessPro and CollectPro applications using Visual Basic 6 (VB6).
- Refined existing software code to boost responsiveness and fulfill customer expectations.
- Formulated and implemented SQL queries, scripts, and stored procedures.
Technologies: Visual Basic 6 (VB6), SQL, Microsoft SQL Server, SQL Server 2008 R2, SQL Stored Procedures, Complex SQL Queries, SQL Views, Cross-functional Collaboration, Cross-departmental Collaboration, Back-end, Back-end Development, Engineering, Databases, Desktop App Development, Object-oriented Programming (OOP), PL/SQL, ASP.NET Web Forms
Software Engineer
2011 - 2012
S&P Global
- Developed and optimized front- and back-end applications using C# and Perl, including automation tools and client-facing platforms.
- Enhanced cross-server functionality and updated legacy code for better performance.
- Executed advanced data manipulation with Oracle and SQL queries and managed SQL Server 2008 R2 databases.
- Delivered round-the-clock, 24/7 on-call support on a rotational basis to ensure product reliability and uphold customer satisfaction.
Technologies: C#, Perl, SQL, Microsoft SQL Server, Oracle, .NET, Toad, Cross-functional Collaboration, Cross-departmental Collaboration, Visual Studio 2008, SQL Server 2008 R2, SQL Stored Procedures, SQL Views, Complex SQL Queries, Back-end, Back-end Development, Windows Forms (WinForms), Front-end, Front-end Development, Engineering, Full-stack Development, Databases, Desktop App Development, C#.NET, Object-oriented Programming (OOP), Oracle Database, PL/SQL, ASP.NET Web Forms
Experience
Routary
https://routary.comAn innovative web application focused on providing advanced route optimization solutions for businesses and individuals.
As a co-founder and lead back-end architect, I drove the creation of a sturdy infrastructure using .NET and complementary technologies, focusing on performance, scalability, and reliability. I also worked on system design, back-end service implementation, and database optimization.
Routary enhances logistics efficiency, reduces costs, and improves delivery times through sophisticated algorithms and seamless integration with various mapping and transportation APIs.
As a co-founder and lead back-end architect, I drove the creation of a sturdy infrastructure using .NET and complementary technologies, focusing on performance, scalability, and reliability. I also worked on system design, back-end service implementation, and database optimization.
Routary enhances logistics efficiency, reduces costs, and improves delivery times through sophisticated algorithms and seamless integration with various mapping and transportation APIs.
ParcelRobin
An innovative shipping label aggregator platform focused on providing discount shipping labels to businesses and individuals.
As the co-founder and lead back-end engineer, I spearheaded the development of a robust back-end infrastructure, leveraging my expertise in .NET and other technologies to ensure high performance, scalability, and reliability. My responsibilities included designing the system architecture, implementing critical back-end services, and optimizing database performance.
We had over 1,000 repeat customers on the platform and over $100,000 in recurring annual revenue.
As the co-founder and lead back-end engineer, I spearheaded the development of a robust back-end infrastructure, leveraging my expertise in .NET and other technologies to ensure high performance, scalability, and reliability. My responsibilities included designing the system architecture, implementing critical back-end services, and optimizing database performance.
We had over 1,000 repeat customers on the platform and over $100,000 in recurring annual revenue.
CI/CD Application
A robust CI/CD application using C# at NutriSavings. The application interacted with TortoiseSVN by calling command line queries to detect new commits, initiate builds on the committed code, run SQL scripts, and notify subscribers of the build results. Additionally, it featured deployment capabilities to various environments based on specified flags.
Education
2005 - 2010
Bachelor's Degree in Electrical Engineering
McGill University - Montreal, Canada
Certifications
MAY 2024 - MAY 2026
Contentful Certified Professional
Contentful
MAY 2024 - MAY 2027
AWS Certified Cloud Practitioner
Amazon Web Services Training and Certification
Skills
Libraries/APIs
EasyPost, Stripe API, REST APIs, Back-end APIs, Complex SQL Queries, API Development, Stripe, Google API, Google Routes API, Google Geocoding API, Jenkins Pipeline, Entity Framework, Vue 3, Sinon.JS, jQuery, Google APIs, Vue, Bitbucket API, PrimeVue, Handlebars, Google Cloud API, Windows Forms (WinForms), DigitalOcean API
Tools
Visual Studio, Git, Jira, Slack, Zoom, Visual Studio 2019, Visual Studio 2010, Google Docs, WebStorm, MySQL Workbench, Postman, RabbitMQ, Kentico, TortoiseSVN, GitHub, Microsoft Teams, Google Workspace, Visual Studio 2008, pgAdmin, Amazon Simple Queue Service (SQS), Jenkins, AWS CloudFormation, Bitbucket, Citrix XenApp, VMware vSphere, Bamboo, Amazon WorkSpaces, VMware vSphere HA, xUnit, TortoiseCVS, Microsoft Team Foundation Server, TFS, Toad, cURL Command Line Tool
Languages
C#, SQL, C#.NET, VB.NET, GraphQL, TypeScript, CSS, Visual Basic 6 (VB6), Perl, YAML, Python, JavaScript, TypeScript 3, HTML
Frameworks
.NET Core, ASP.NET, .NET, Scaled Agile Framework (SAFe), Swagger, ASP.NET Web Forms, Windows PowerShell, NUnit, Aurelia, Angular, Angular 6
Paradigms
REST, Agile, API Architecture, Back-end Architecture, Database Design, Agile Software Development, Object-oriented Programming (OOP), Desktop App Development, Kanban, Azure DevOps, Continuous Deployment, Continuous Delivery (CD)
Platforms
Windows, Visual Studio Code (VS Code), Mailgun, Visual Studio 2022, Visual Studio 2017, Linux, Azure, Google Cloud Platform (GCP), CentOS, Contentful, Oracle, AWS IoT, DigitalOcean, Apache Kafka, Amazon Web Services (AWS), WordPress, Docker, Ubuntu, Azure Functions, Oracle Database
Storage
MySQL, Microsoft SQL Server, SQL Stored Procedures, SQL Functions, Databases, PL/SQL, SQL Server 2016, Redis Cache, PostgreSQL, JSON, SQL Server 2008 R2, SQL Views, Elasticsearch, Redis, Google Cloud, SQL Server Reporting Services (SSRS)
Other
.NET 8, .NET 6, .NET Framework, .NET 7, Back-end, Cross-functional Collaboration, Webhooks, Back-end Development, Remote Work, API Documentation, Cross-departmental Collaboration, Relational Database Design, APIs, Engineering, System Design, API Integration, Startups, Integration, Multithreading, Front-end, Full-stack, Mentorship, Mentorship & Coaching, Leadership, Architecture, Message Queues, Software Architecture, IIS, Web Server (IIS), Full-stack Development, Web Development, Software as a Service (SaaS), Payment APIs, CI/CD Pipelines, Technical Leadership, Content Management Systems (CMS), API Design, Azure Data Studio, Electrical Engineering, AWS CodePipeline, GitHub Actions, .NET Core 2, SSRS Reports, GraphQL Federation, User Experience (UX), Team Leadership, Front-end Architecture, Front-end Development, Windows Services, Azure CLI, OpenAI, OR-Tools, Microsoft Azure
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