Lav Kumar Vishwakarma, Developer in Bhopal, Madhya Pradesh, India
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Lav Kumar Vishwakarma

Verified Expert  in Engineering

Web Security Developer

Bhopal, Madhya Pradesh, India
Toptal Member Since
June 24, 2022

Lav is a back-end engineer with 8+ years of experience building scalable, secure, and distributed applications. Lav has worked with startups and enterprises to build various SaaS products. His expertise lies in architecture design, development, and deployment of innovative products from scratch. Lav's specialties include Go, PostgreSQL, microservices, GraphQL, Java, and Spring Boot.


Java, Spring Boot, Keycloak, OAuth 2, Stripe, Apple Pay...
Java, Spring Boot, MongoDB, Keycloak, Miro, Amazon Web Services (AWS)...
Go, Microservices, gRPC, REST, Protobuf, Docker, Kubernetes, PostgreSQL...




Preferred Environment

Go, GoLand, PostgreSQL, Git, Jira, gRPC, REST, Microservices, Docker, MacOS

The most amazing...

...things I've built are a personal development platform at GrowthDay and scheduling products for enterprises like Google and Telefonica.

Work Experience

Lead Software Engineer

2021 - PRESENT
  • Oversaw the development of back-end application architecture and system design for a personal development platform that includes live coaching sessions to help 200,000 active users build confidence, develop good habits, and improve their lifestyles.
  • Spearheaded the development of a new enterprise product to introduce the GowthDay brand to SMEs and help each client build successful teams, emphasizing good communication, fostering company culture, and driving efficiency at scale.
  • Developed new platform features, including a video conferencing system, enabling collaborative learning and gift subscriptions to drive user growth.
  • Collaborated with executive stakeholders and design, front-end, and product teams to define technical product requirements, determine product features, and streamline an overall development roadmap.
  • Supervised hiring and training of a back-end development team and collaborated with cross-functional leaders to deliver multiple complex projects.
Technologies: Java, Spring Boot, Keycloak, OAuth 2, Stripe, Apple Pay, Amazon Web Services (AWS), Amazon Elastic Container Service (Amazon ECS), MongoDB, Microservices, REST, Kajabi, Jira, Miro, Sentry, Analytics, Architecture, SQL, APIs, Zapier, Back-end Development, Cloud Services

Back-end Engineer

2021 - 2021
  • Led the revamp of the back-end development by rebuilding the app's core pillars from scratch, improving development processes, optimizing the developer experience, and driving enhancements to enable reusability, security, and increased performance.
  • Enhanced the API performance and made it production-ready by implementing notifications, error reporting, centralizing logging, scaling, improving the response time, and providing support for regulatory compliance.
  • Contributed to different analytics platform integrations like the Facebook pixel, Mixpanel, Google Analytics, and AppsFlyer.
Technologies: Java, Spring Boot, MongoDB, Keycloak, Miro, Amazon Web Services (AWS), Amazon Elastic Container Service (Amazon ECS), OAuth 2, REST, Analytics, SQL, APIs, Zapier, Google Analytics, Back-end Development, Cloud Services

Lead Software Engineer

2019 - 2021
  • Led the development of SaaStack, a SaaS platform, including designing the plug-and-play architecture for the back end with inbuilt scaling, security, and regulatory compliance handling.
  • Contributed to core architecture layers, including authentication, roles and rights, licensing, logging, tracing, and scalability.
  • Developed new features for SaaStack to support people, account, client billing, and enterprise management using Go, GraphQL, gRPC, and PostgreSQL.
  • Enhanced performance, reducing the API response times from two seconds to less than 150 milliseconds.
  • Assisted with the scaffolding app's command-line interface tools by leveraging Relay as a GraphQL client to eliminate the codebase set-up time and leveraging a protocol buffer to generate the Go service codebase.
  • Decreased development time and maximized development flexibility by developing a set of code generation tools based on easy-to-use annotations and reduced the development time by 80% of code generation.
  • Created guides and checklists for developers, worked on improving developer experience, and mentored developers to increase their efficiency.
Technologies: Go, Microservices, gRPC, REST, Protobuf, Docker, Kubernetes, PostgreSQL, MongoDB, SQL Server 2016, WebSockets, GraphQL, JSON Web Tokens (JWT), Hydra, OAuth 2, Web Architecture, NATS, Google Cloud Platform (GCP), Azure, Git, GoLand, Jira, Documentation, Payment APIs, Stripe, Square,, Zoho, SQL, APIs, Zoho CRM, Zapier, Microsoft Excel, Airtable, Google Analytics, Back-end Development, Customer Relationship Management (CRM), Cloud Services

Product Developer

2017 - 2019
  • Developed Appointy's small-to-large business scheduling tool based on microservice architecture. The tool is used by one million people.
  • Evaluated integration libraries and tools to shorten the development time from one year to one month. Designed microservices and the micro front-end architecture to help further optimize development.
  • Advised and oversaw client development by creating user flows, product roadmaps, and features with a team of eight back-end developers.
  • Created a new product that coordinated fitness classes, restaurants, and spa scheduling for Google.
  • Built a room conference scheduling system for Telefonica, one of Spain's largest telecom companies, with features for managing rooms, scheduling calendars, staffing, and CMS and TMS integrations.
Technologies: C#, IIS, SQL Server 2016, Azure, Docker, REST, Microservices, OAuth, Stripe, Square,, PayPal, Mixpanel, WebSockets, TMS, .NET 5, .NET Core, Go, PostgreSQL, Kubernetes, Web Security, SQL, APIs, Zapier, Microsoft Excel, Airtable, Back-end Development, Customer Relationship Management (CRM), Cloud Services

Associate Product Developer

2015 - 2017
  • Integrated a stripe payment system for accepting recurring and one-time payments and created a payment monitoring system to track and manage payments.
  • Worked on the spam email checker script, which verified the existence of emails and reduced the email bounce rate by 99.9%.
  • Reviewed system implementation for getting more reviews from the customers and increased the review ratio by 40%.
Technologies: Stripe, Node.js, Bash Script, REST, HTML, CSS, JavaScript, Zapier, System Implementation

Conferencing Portal for Telefonica

Designed the conference scheduling and management portal from scratch and communicated and collaborated with Telefonica's Madrid team. In addition, I worked on technologies including .NET Web API 2 and microservices. The project was integrated with CMS and TMS Cisco technologies and LDAP.

GrowthDay App
Collaborated on GrowthDay, the world's first all-in-one personal development app. It empowers people in 190 countries and encourages them to use the tools, content, coaching, and community to grow and achieve their dreams. The app features live weekly training sessions by the world's best coaches and custom personal growth tools for journaling, online challenges, goal setting, habit scoring, life assessments, and community participation.

Appointy X
I developed the back-end architecture, built basic apps, and created various components for the team. Appointy X is a web-based SaaS product for scheduling classes, appointments, events, and meetings. This newer version based on SaaStack was written in a different stack from the ground up.

Led the development of SaaStack, a SaaS platform, and designed the plug-and-play architecture for the back end with inbuilt scaling, security, and regulatory compliance handling. In addition, I contributed to the architecture core layers, including authentication, roles and rights, licensing, and default libraries.

Appointy 9
I headed the entire back-end development for a web-based SaaS product for scheduling classes, appointments, events, meetings, and rooms. The project included selecting technologies for creating modular architecture and writing more than 90% of the back-end code. The product's components are used by Google and Telefonica.
2013 - 2017

Bachelor's Degree in Computer Science

University Institute of Technology, RGPV - Bhopal, India


Certified Ethical Hacker (CEH)



Protobuf, Stripe, Stripe API, Node.js,, Mixpanel API, Twilio API, Pushwoosh, Web API 2


GoLand, Git, Jira, IntelliJ IDEA, Sentry, Zapier, Microsoft Excel, RabbitMQ, NGINX, Miro, Keycloak, OneSignal, Jenkins, Google Analytics, ChatGPT, Istio, Amazon Elastic Container Service (Amazon ECS)


OAuth 2, gRPC, JSON Web Tokens (JWT), Spring Boot, Express.js, Hydra, .NET 5, .NET Core


Go, Java, GraphQL, HTML, SQL, C#, CSS, JavaScript, Bash Script


REST, Microservices, Serverless Architecture, Web Architecture


Google Cloud Platform (GCP), Software Design Patterns, Docker, Azure, Amazon Web Services (AWS), Windows Server, Linux, Zoho CRM, LearnWorlds, Kubernetes, Kajabi, Mixpanel, MacOS


PostgreSQL, SQL Server 2017, MongoDB, Redis, MySQL, Memcached, Elasticsearch, Azure Active Directory, SQL Server 2016


Software Development, Web Security, WebSockets, NATS, Server Security, Cloud Security, Development, Architecture, Documentation, Payment APIs, Web Server (IIS), Software as a Service (SaaS), Identity Server, Back-end, Zoho, APIs, Back-end Development, Cloud Services, Sharding, LDAP, Domain-driven Design (DDD), Telemetry, Load Balancers, Square, Apple Pay, TMS, Analytics, SAML-auth, Scalable Architecture, Maps, Airtable, Customer Relationship Management (CRM), Infrastructure Security, IIS 7, ECS, IIS, OAuth, PayPal, System Implementation

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