Sajith Herath

I am a Python backend engineer with 6 years of experience, dedicated to building reliable, high-performance systems that deliver results every time. My recent work focuses on integrating large language models (LLMs), AI automation, and agentic workflows-ensuring that the solutions I develop are both innovative and robust.

Through hands-on experience with scalable architectures, I have developed a strong command of the design patterns, frameworks, and tools essential for dependable software at scale. I am committed to high-quality testing and rapid validation cycles, always striving to deliver solutions that are both correct and efficient.

I enjoy tackling challenging problems at the intersection of backend engineering and artificial intelligence, and I’m always eager to learn and apply the latest technologies.

Outside of work, I’m passionate about calisthenics, traveling, and capturing the beauty of nature through photography. I value connecting with others and am always open to new ideas and collaborations.

Senior Software Engineer – Python (AI/ML, LLM & Agentic Workflow Integration)
PRIMESENS LLC | Aug 2022 – Present
- Architected and developed LLM-powered microservices for a CRM, featuring intelligent lead scoring and an agentic AI chatbot to streamline customer interactions and prioritize deals
- Developed an LLM-based analyzer to automatically extract and unify tabular data from diverse rent roll and T12 financial documents (PDFs/spreadsheets), accelerating real estate analysis
- Reduced AWS server costs by 89% by designing a GPU-accelerated video transcoding solution as an alternative to AWS MediaLive
- Engineered a real-time closed captioning engine utilizing speech-to-text machine learning models
- Developed multivariate time series forecasting models for geo-specific mortgage rates, delivering insights to enhance financial analysis and investment strategies
- Engineered a recommendation system using Collaborative Filtering and a CNN facial classifier to power 3D/AR try-on experiences, enhancing e-commerce personalization
- Designed and deployed scalable microservices for a unified social media management platform, integrating Facebook, Instagram, X, and LinkedIn APIs, managed via Kubernetes
- Developed high-throughput post schedulers for complex media files and optimized data analysis across 50+ metrics for key social media insights Tech Stack: Python, FastAPI, Langchain, Docker, Kubernetes, AWS, GCP

Self Employed​ Software Engineer | Oct 2020 – Aug 2021
- Built and scaled automated ETL pipelines for SEC Form 4 data, processing 5 million historical records and over 3,000 daily filings for insider trading analytics
- Developed and maintained web scrapers covering over 8,000 companies, enriching Form 4 datasets to deliver actionable trading insights
- Designed and implemented REST APIs (FastAPI) and microservices, including real-time video streaming solutions using AWS Chime, FFMPEG, and WebRTC
- Implemented DevOps pipelines and managed cloud deployments across AWS, GCP, and Azure, leveraging Kubernetes and CI/CD automation for resilient and scalable software delivery

Software Engineer – Machine Learning
Arimac Lanka (pvt) Limited​ | Jul 2019 – Sept 2020
- Engineered multi-platform integrations for a social listening tool, expanding data extraction across various channels for comprehensive analysis of trends, conversations, and brand sentiment
- Integrated SERP analysis into the social listening tool, enabling extraction of web search data to provide richer context alongside social media analysis

Software Engineer Intern
Fortunaglobal (Pvt) Limited | Jul 2017 – Jul 2018
- Developed fintech chatbots using fuzzy logic and sequence ML models to automate customer inquiries and provide secure access to online banking functionalities
- Built a dashboard visualizing chatbot interactions and managed secure on-premise deployment, ensuring compliance with strict banking security standards

Education

BEng in Software Engineering (First Class Honours)
University of Westminster | 2015 – 2019


Core Interests & Skills

LLMs & Generative AI: Integration, fine-tuning, and workflow automation with large language models.
Agentic Workflows: Designing autonomous, adaptive AI systems for business process automation.
Backend Engineering: Scalable Python APIs, microservices, and cloud-native architectures.
Machine Learning: Recommendation systems, NLP, and predictive analytics.
DevOps & Cloud: Docker, Kubernetes, AWS, GCP, CI/CD.


Let’s Connect

I’m always open to collaborating on innovative AI projects or discussing the future of agentic automation.
Feel free to reach out or explore my portfolio for more!