Lakshan is available for hire
Hire LakshanLakshan Hettiarachchi
Verified Expert in Engineering
Back-end Developer
Kandana, Western Province, Sri Lanka
Toptal member since October 26, 2021
Bio
Lakshan is a senior back-end engineer with 10+ years of experience designing and building high-performance enterprise software. He has completed 6,500+ hours of successful Toptal engagements and has contributed to large-scale OTT streaming platforms, airline systems, content analytics solutions, and retail applications. Specializing in Java, distributed systems, microservices, and cloud technologies, he excels at delivering robust, scalable solutions to complex business problems.
Portfolio
Endeavor - Streaming DBA Dice Technology
Java, Amazon DynamoDB, Amazon RDS, Amazon Elastic Container Service (ECS)...
Grey Orange Inc.
Java, REST APIs, Spring, NoSQL, MongoDB, Auth0, Google Cloud Platform (GCP)
Sintelix
Java, Apache Lucene, JavaScript, Cdata, ABBYY FineReader OCR API, JSON...
Experience
- Java - 6 years
- REST - 6 years
- Spring Boot - 5 years
- gRPC - 4 years
- Apache Kafka - 3 years
- Micro SOA - 3 years
- Couchbase - 3 years
- PostgreSQL - 3 years
Work Experience
Java Developer
2025 - PRESENT
Endeavor - Streaming DBA Dice Technology
- Designed and delivered back-end features across Java-based microservices supporting content discovery, subscription management, user identity, personalization, and video-on-demand workflows.
- Implemented content licensing and availability capabilities, including geo-restriction handling, sunset-content filtering, entitlement evaluation, and content accessibility rules.
- Developed and enhanced Download-to-Go (offline viewing) policy frameworks across ingestion, licensing, and VOD services, enabling device-specific download controls and rights management.
- Built system-defined watchlist (My List) functionality and content personalization capabilities used to deliver curated and user-specific content experiences.
- Implementation of configurable profile and realm-level feature management, enabling platform teams to control user experience through centralized configuration.
- Implemented search and content-discovery improvements, including custom content lists, search filtering enhancements, and content indexing optimizations.
- Diagnosed and resolved complex production issues involving caching, memoization, content availability evaluation, and distributed service interactions.
- Collaborated across multiple engineering teams to deliver end-to-end solutions spanning front-end integrations, back-end services, APIs, data models, and platform infrastructure.
- Maintained a strong focus on software quality through automated testing, code reviews, regression validation, and continuous integration practices.
- Worked as a back-end engineer on a large-scale microservices-based streaming and subscription platform powering multiple OTT brands owned by AMC Global Media.
Technologies: Java, Amazon DynamoDB, Amazon RDS, Amazon Elastic Container Service (ECS), Dropwizard, Quarkus, Apache Maven, Docker, JUnit 5, Mockito, WireMock, AssertJ, Jackson, REST APIs, Microservices Architecture, GitHub, CI/CD Pipelines, Jenkins, Confluence, Jira, Terraform
Senior Software Engineer (Java)
2023 - 2024
Grey Orange Inc.
- Gained expertise in omnichannel sales processes within the apparel retail industry.
- Developed and maintained the Java back end for the gStore inventory management and fulfillment application.
- Designed and implemented data persistence and aggregation queries using MongoDB and its aggregation pipeline.
Technologies: Java, REST APIs, Spring, NoSQL, MongoDB, Auth0, Google Cloud Platform (GCP)
Full-stack Java Developer
2021 - 2023
Sintelix
- Integrated and configured ABBYY FineReader OCR API with Sintelix.
- Worked with Cdata connectors such as CSV, JSON, MongoDB, MySQL, Oracle OCI, PostgreSQL, SQL Server, IBM DB2, Microsoft Excel, and XML to facilitate data ingestion to Sintelix. In addition, certain GUI components were also built to filter the data.
- Implemented an audit functionality to track ingestion and changes to the documents ingested to Sintelix. This included a UI for filtering and viewing audit entries.
- Designed and implemented a license quota usage tracker in Sintelix to record the usage of different quota types, such as text, OCR, and media, and display it on a UI. The quota consumption records were modeled as a blockchain to maintain integrity.
- Created a blueprint to secure and enhance the licensing and activation key mechanism of SIntelix online and offline clients to minimize the tampering of licensed quota usage while being client-friendly on offline usage reporting.
Technologies: Java, Apache Lucene, JavaScript, Cdata, ABBYY FineReader OCR API, JSON, Continuous Integration (CI), Git, Databases, Relational Databases, Oracle, Full-stack, Object-oriented Programming (OOP), API Integration, Front-end Development, HTML, CSS, HTTP REST, Optical Character Recognition (OCR), Full-stack Development, CI/CD Pipelines
Tech Lead
2020 - 2022
ACCELaero Portfolio
- Played a key role in feature development, performance testing, performance tuning, and facilitation for multiple government certifications during and after the inaugural production release of the aeroCONNECT aviation messaging system.
- Developed parsers using ANTLR and JavaCC for various airline message types, such as PNRGOV and SSIM, in formats such as EDIFACT. In addition, these messages were also created using FreeMaker and Apache Velocity to facilitate 2-way communication.
- Worked on production stabilization and change and feature request development for the aeroPRICE airline ticket pricing system.
- Developed flows, such as inventory roll forward, inventory transfer, and reprotection of aeroINVENTORY, the airline seat inventory system.
- Provided Level 3 support on a monthly roster basis for the aeroCONNECT airline messaging system and the aeroPRICE airline pricing system.
- Conducted employee training sessions on Apache Kafka.
- Participated in recruiting, training, ranking, and placement of experienced, fresh, and undergraduate developers.
Technologies: Java, Spring Boot, Apache Kafka, PostgreSQL, gRPC, Protobuf, REST, Docker, JUnit, Mockito, SonarQube, JProfiler, Couchbase, Microservices Architecture, Spring Microservice, Microservices, Spring Data JPA, Web Platforms, APIs, Solution Architecture, SQL, Architecture, Software Architecture, OAuth 2, Scrum, Jira, PowerMock, NoSQL, Message Queues, REST APIs, Technical Hiring, Interviewing, IntelliJ IDEA, Code Review, Source Code Review, Back-end, Containers, Design Patterns, Distributed Systems, Task Analysis, JSON, Spring, Continuous Integration (CI), Git, Databases, API Development, Relational Databases, Scalable Architecture, Scalable Application, Object-oriented Programming (OOP), API Integration, Debezium, Integration, EDIFACT, Electronic Data Interchange (EDI), HTTP REST, Amazon Web Services (AWS), ActiveMQ, CI/CD Pipelines, Real-time Streaming, MQTT, RabbitMQ, AWS Certified Solution Architect, Cloud Architecture
Senior Software Engineer
2018 - 2019
ACCELaero Portfolio
- Worked on architectural design, technology selection and training, development, testing, production stabilization, and support of microservices and the aeroCONNECT stream processing-based messaging system using Spring Boot, Kafka, and Couchbase.
- Developed parsers using ANTLR and JAVACC for various airline message types, such as PNRGOV and SSIM, in formats such as EDIFACT. In addition, these messages were also created using FreeMaker and Apache Velocity to facilitate 2-way communication.
- Conducted employee training and evaluation on the Couchbase NoSQL database.
- Enhanced the aeroLINE FLEET aircraft rotation and routing system to automatically reschedule flights based on the receiving air traffic flow and capacity management (ATFCM) messages.
Technologies: Java, Spring Boot, Apache Kafka, Amazon Web Services (AWS), Couchbase, gRPC, Protobuf, REST, Java Message Service (JMS), IBM MQ, ANTLR, Docker, JUnit, Mockito, SonarQube, Jenkins, Jira, Microservices Architecture, Spring Microservice, Microservices, Spring Data JPA, Web Platforms, APIs, Solution Architecture, SQL, Architecture, Software Architecture, Scrum, PowerMock, NoSQL, Message Queues, REST APIs, Redis, Technical Hiring, Interviewing, IntelliJ IDEA, Code Review, Source Code Review, Back-end, Containers, Design Patterns, Distributed Systems, Task Analysis, JSON, Spring, Continuous Integration (CI), Git, Databases, API Development, Relational Databases, Oracle, Scalable Architecture, Scalable Application, Object-oriented Programming (OOP), API Integration, Constraint Programming, Operations Research, Integration, EDIFACT, Electronic Data Interchange (EDI), ActiveMQ, CI/CD Pipelines, Real-time Streaming, MQTT, RabbitMQ, AWS Certified Solution Architect, Cloud Architecture
Research and Development Engineer
2016 - 2018
ACCELaero Portfolio
- Researched and developed genetic algorithm-based airline crew scheduling and rostering algorithms in Java to distribute duties and pairings among different types of flight and cabin crew.
- Devised mathematical formulae to calculate roster cycle targets for flight and cabin crew members on entities, such as flying hours and duty hours, while respecting their annual, quarterly, and monthly limits on flying and duty hours.
- Programmed crew duty and fatigue-related rules in the crew rostering system back end in Java to facilitate the generation of legal rosters.
- Analyzed airline operation manuals to identify the requirements of new client airlines and accommodate their crew management and rostering requirements.
- Created BIRT reports, such as journey logs and duty sheets, generated from airline crews' duty data.
- Assisted technical writers with technology and domain knowledge while they compiled user manuals for the airline crew management system.
Technologies: Java, Spring Boot, Oracle Database, BIRT, Algorithms, Hibernate, Web Platforms, SQL, Scrum, Jira, PowerMock, REST APIs, IntelliJ IDEA, Back-end, Design Patterns, Spring, Continuous Integration (CI), Git, Databases, Relational Databases, Oracle, Object-oriented Programming (OOP), Constraint Programming, Operations Research
Research and Development Intern
2015 - 2016
ACCELaero Portfolio
- Worked on mathematical models and algorithms that automatically distribute cargo inside an aircraft and achieve an aircraft's safe and efficient weight and balance configuration. I used FICO Xpress and Java in these projects.
- Developed algorithms that solved the aircraft rotation and routing problem using FICO Xpress and Java.
- Built an IATA SSIM message parser to automatically extract data in a standard SSIM message using the JavaCC parser generator.
- Proposed a graphical solution to enable crew planners and schedulers to independently program the crew and fatigue-related rules into the automated crew rostering system.
- Researched machine learning-related algorithms to improve the quality of the flight and cabin crew rosters in automatic rostering concerning fairness and robustness.
- Investigated the suitability of graph databases (Neo4j) over relational databases (Oracle Database) to represent and store data related to airline crews and duties.
Technologies: FICO Xpress, Linear Programming, Java, Oracle Database, JavaCC, Algorithms, SQL, IntelliJ IDEA, NoSQL, Back-end, Git, Databases, Relational Databases, Object-oriented Programming (OOP), Constraint Programming, Operations Research
Project History
aeroCONNECT
A cloud-based messaging middleware for airline, airport, and government software systems that rely on aviation messaging for communication. This system caters to high throughput and scalability by its design of microservices and stream processing-based architecture. aeroCONNECT also communicates bidirectionally with external systems, creates and parses aviation messages (such as PNRGOV, SSM, and ASM in EDIFACT and text formats), and delivers and accepts messages from client systems with persistence and high availability.
Air Arabia currently uses this system in all of its hubs. It has provided a centralized platform for users to manage millions of messages of various specifications during the day-to-day operation of the airline. The integration time of new messages was reduced to two days as a result of this system and its architecture.
I was involved in architecture design, technology selection and training, development, testing, production stabilization, and support.
Air Arabia currently uses this system in all of its hubs. It has provided a centralized platform for users to manage millions of messages of various specifications during the day-to-day operation of the airline. The integration time of new messages was reduced to two days as a result of this system and its architecture.
I was involved in architecture design, technology selection and training, development, testing, production stabilization, and support.
aeroINVENTORY
An airline seat inventory management system built for Air Arabia. It provides an interactive UI for the users to create and manage seat inventory for flights and APIs to integrate with other systems in the airline's operations. I joined this project midway through its development and went on to develop key features, such as inventory roll forward, inventory transfer, and reprotection.
aeroPRICE
A system for creating and managing airline ticket prices and surcharges. It provides a UI for users and APIs for integration with the product ecosystem. I joined the project after its production release and worked on production stabilization and feature request development to improve the client experience and add value to their operations.
aeroLINE CREW
An essential system used by airlines to manage, pair, and roster flight and cabin crew for their duties. It prominently solved the crew scheduling problem for Air Arabia.
I was engaged with this product for 2+ years, developing the algorithm that distributes crew to pairings and duties. I used a modified genetic algorithm to improve the quality of the output of the solution. I was also involved in understanding airline fatigue-related rule manuals; programming the rules into the system; developing a formula for fair distribution of flight hours, duty hours, and various duty types among the crew; developing reports; and assisting technical writers with product knowledge for the manuals they wrote.
I was engaged with this product for 2+ years, developing the algorithm that distributes crew to pairings and duties. I used a modified genetic algorithm to improve the quality of the output of the solution. I was also involved in understanding airline fatigue-related rule manuals; programming the rules into the system; developing a formula for fair distribution of flight hours, duty hours, and various duty types among the crew; developing reports; and assisting technical writers with product knowledge for the manuals they wrote.
aeroLINE FLEET
A system to keep aircraft utilization high by managing airline fleets while efficiently scheduling aircraft to flights and maintenance procedures. I worked on designing and developing the aircraft rotation and routing algorithm, using the FICO Xpress optimizer, linear programming, and Java.
aeroPORT TRIM
An application to achieve safe and efficient weight and balance of Air Arabia's fleet of A320 aircraft. The core of this system relied on linear programming and operations research and was built using Java and FICO Xpress optimizer. As an intern, I worked on the optimization algorithm for this product and documented it for future reference.
Education
2013 - 2017
Bachelor's Degree in Computer Science and Engineering
University of Moratuwa - Moratuwa, Sri Lanka
Certifications
AUGUST 2023 - AUGUST 2026
AWS Certified Solutions Architect - Associate
Amazon Web Services (AWS)
Skills
Libraries/APIs
Protobuf, REST APIs, API Development, Java Message Service (JMS), Apache Lucene, AssertJ, Jackson
Tools
IntelliJ IDEA, IBM MQ, ANTLR, SonarQube, Jenkins, Jira, Git, ActiveMQ, MQTT, RabbitMQ, JavaCC, JProfiler, Amazon Elastic Container Service (ECS), Apache Maven, WireMock, GitHub, Confluence, Terraform, DataGrip, Auth0
Languages
Java, SQL, C, JavaScript, HTML, CSS
Frameworks
gRPC, Spring Boot, Spring, JUnit, Mockito, PowerMock, Hibernate, Spring Microservice, OAuth 2, Dropwizard, JUnit 5
Paradigms
Design Patterns, Object-oriented Programming (OOP), Constraint Programming, Scrum, Microservices, Microservices Architecture, Continuous Integration (CI), Scalable Application, Linear Programming, REST
Platforms
Apache Kafka, Amazon Web Services (AWS), Oracle Database, Ubuntu, Oracle, Debezium, Docker, BIRT, Google Cloud Platform (GCP)
Storage
Databases, Relational Databases, Couchbase, PostgreSQL, Spring Data JPA, NoSQL, MySQL, JSON, Neo4j, Redis, Amazon DynamoDB, MongoDB
Other
Software Architecture, Architecture, Solution Architecture, APIs, Technical Hiring, Interviewing, Code Review, Source Code Review, Back-end, Distributed Systems, API Integration, Integration, EDIFACT, Electronic Data Interchange (EDI), AWS Certified Solution Architect, Micro SOA, Algorithms, Web Platforms, Message Queues, Containers, Task Analysis, ABBYY FineReader OCR API, Scalable Architecture, Operations Research, Optical Character Recognition (OCR), CI/CD Pipelines, Real-time Streaming, Cloud Architecture, FICO Xpress, Cdata, Full-stack, Front-end Development, HTTP REST, Full-stack Development, Amazon RDS, Quarkus
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