Aggelos – Typescript, AWS, Node.js

B2B infrastructure planning platform helping water utilities analyze large water networks, reduce infrastructure risk, and optimize capital and sensor-placement decisions.

• Built a distributed leak-monitoring optimization engine that selects sensor locations across large water distribution networks to maximize coverage. • Modeled sensor placement as an Integer Linear Programming problem and designed a coordinator-worker architecture on AWS Lambda to partition networks, fan out solver workloads, and merge results. • Built and maintained full-stack systems operating on datasets representing millions of physical assets, including large-scale geospatial queries and ESRI-compatible data pipelines. • Worked across PostgreSQL and MongoDB, applying data modeling, indexing, query optimization, and caching strategies for data-heavy workloads. • Owned features end to end across backend services, React interfaces, AWS infrastructure, testing, and production rollout. • Worked closely with DevOps on AWS and CDK infrastructure and introduced DORA delivery metrics to improve visibility into engineering performance. • Took ownership of the release lifecycle and release strategy, helping increase deployment frequency from roughly monthly releases to several releases per week.

An enterprise B2B e-commerce platform built specifically for supermarkets, grocery retail chains, and FMCG brands.

• Built and maintained Node.js and TypeScript backend services for core e-commerce workflows, delivery logic, merchant operations, and OpenAPI-aligned REST APIs. • Developed real-time distributed workflows using WebSockets and Redis-backed communication for horizontally scaled services. • Designed backend workflows supporting multi-currency, multi-timezone, discount campaigns, delivery timeslots, and merchant-specific business rules. • Led the migration of approximately 300k legacy orders into MongoDB and resolved post-migration performance issues through stress testing, profiling, and targeted indexing. • Investigated production memory leaks and performance bottlenecks using heap snapshots, profiling, Datadog, New Relic, and MongoDB Atlas. • Built and maintained integrations with external ERP systems, synchronizing products, stock, categories, and related commerce data under high traffic. • Maintained a backend codebase with approximately 96% automated test coverage.

Configurable workflow platform that allows organizations to define their own processes, steps, permissions, and business rules instead of relying on fixed application flows.

• Helped consolidate several independent applications into IntelliFlow, a configurable workflow platform that became the company's core product. • Built the platform end to end across React frontends, FastAPI backend services, relational data flows, and production deployment. • Developed backend services supporting complex role-based access control, multi-role permission models, dashboards, and internal operational workflows. • Built React interfaces for both end users and internal administrative workflows. • Worked on Smart Cities and public-sector systems with direct operational use by enterprise and national infrastructure organizations. • Containerized applications with Docker and handled deployment, configuration, monitoring, and troubleshooting on unmanaged Linux infrastructure. • Delivered product and performance improvements across the platform while working directly across frontend, backend, and infrastructure concerns.